Genetic Phenomena Commons^™

Monitoring Pd-L1 Expression On Circulating Tumor-Associated Cells In Recurrent Metastatic Non-Small-Cell Lung Carcinoma Predicts Response To Immunotherapy With Radiation Therapy, Jillian A Moran, Daniel L Adams, Martin J Edelman, Pablo Lopez, Jianzhong He, Yawei Qiao, Ting Xu, Zhongxing Liao, Kirby P Gardner, Cha-Mei Tang, Steven H Lin

Faculty, Staff and Student Publications

Purpose: Current diagnostic methods to determine programmed death 1 (PD-1) receptor and its ligand (PD-L1)/PD-1 immunotherapy (immune checkpoint inhibitor [ICI]) efficacy in recurrent or metastatic non-small-cell lung carcinoma (rmNSCLC) are imprecise. Although previously shown that patients with high tumor PD-L1 (≥ 50%) demonstrate clinical benefit in the form of disease reduction and improved survival, patients with low PD-L1 (< 50%) sometimes benefit from treatment. Since the PD-L1/PD-1 pathway is dynamic, monitoring PD-L1 levels during treatment may be more accurate than a static baseline tumor biopsy; however, rebiopsying the primary or metastatic disease is rarely feasible. Liquid biopsies that measure the upregulation of PD-L1 on tumor-associated cells (TACs), ie, cancer-associated macrophage-like cells and circulating tumor cells, have been performed, but their predictive value for ICI therapy efficacy is unknown.

Materials and methods: We initiated a single-blind prospective study to evaluate TAC PD-L1 expression changes in rmNSCLC from blood samples before (T0) and after (T1) treatment with ICI (ICI, n = 41) or without ICI (no ICI, n = 41). Anonymized …

Validation Of Cancer-Type-Dependent Benefit From Immune Checkpoint Blockade In Tmb-H Tumors Identified By The Foundationone Cdx Assay, D J Mcgrail, P G Pilié, N U Rashid, L Voorwerk, M Slagter, M Kok, E Jonasch, M Khasraw, A B Heimberger, N T Ueno, R Ferrarotto, J T Chang, S-Y Lin

Faculty, Staff and Student Publications

No abstract provided.

Biomarkers Beyond Brca: Promising Combinatorial Treatment Strategies In Overcoming Resistance To Parp Inhibitors, Yu-Yi Chu, Clinton Yam, Hirohito Yamaguchi, Mien-Chie Hung

Faculty, Staff and Student Publications

Poly (ADP-ribose) polymerase (PARP) inhibitors (PARPi) exploit the concept of synthetic lethality and offer great promise in the treatment of tumors with deficiencies in homologous recombination (HR) repair. PARPi exert antitumor activity by blocking Poly(ADP-ribosyl)ation (PARylation) and trapping PARP1 on damaged DNA. To date, the U.S. Food and Drug Administration (FDA) has approved four PARPi for the treatment of several cancer types including ovarian, breast, pancreatic and prostate cancer. Although patients with HR-deficient tumors benefit from PARPi, majority of tumors ultimately develop acquired resistance to PARPi. Furthermore, even though BRCA1/2 mutations are commonly used as markers of PARPi sensitivity in …

Estimating The Optimal Linear Combination Of Predictors Using Spherically Constrained Optimization, Priyam Das, Debsurya De, Raju Maiti, Mona Kamal, Katherine A Hutcheson, Clifton D Fuller, Bibhas Chakraborty, Christine B Peterson

Faculty, Staff and Student Publications

Background: In the context of a binary classification problem, the optimal linear combination of continuous predictors can be estimated by maximizing the area under the receiver operating characteristic curve. For ordinal responses, the optimal predictor combination can similarly be obtained by maximization of the hypervolume under the manifold (HUM). Since the empirical HUM is discontinuous, non-differentiable, and possibly multi-modal, solving this maximization problem requires a global optimization technique. Estimation of the optimal coefficient vector using existing global optimization techniques is computationally expensive, becoming prohibitive as the number of predictors and the number of outcome categories increases.

Results: We propose an …

Targeting The Alk-Cdk9-Tyr19 Kinase Cascade Sensitizes Ovarian And Breast Tumors To Parp Inhibition Via Destabilization Of The P-Tefb Complex, Yu-Yi Chu, Mei-Kuang Chen, Yongkun Wei, Heng-Huan Lee, Weiya Xia, Ying-Nai Wang, Clinton Yam, Jennifer L Hsu, Hung-Ling Wang, Wei-Chao Chang, Hirohito Yamaguchi, Zhou Jiang, Chunxiao Liu, Ching-Fei Li, Lei Nie, Li-Chuan Chan, Yuan Gao, Shao-Chun Wang, Jinsong Liu, Shannon N Westin, Sanghoon Lee, Anil K Sood, Liuqing Yang, Gabriel N Hortobagyi, Dihua Yu, Mien-Chie Hung

Faculty, Staff and Student Publications

Poly(ADP-ribose) polymerase (PARP) inhibitors have demonstrated promising clinical activity in multiple cancers. However, resistance to PARP inhibitors remains a substantial clinical challenge. In the present study, we report that anaplastic lymphoma kinase (ALK) directly phosphorylates CDK9 at tyrosine-19 to promote homologous recombination (HR) repair and PARP inhibitor resistance. Phospho-CDK9-Tyr19 increases its kinase activity and nuclear localization to stabilize positive transcriptional elongation factor b and activate polymerase II-dependent transcription of HR-repair genes. Conversely, ALK inhibition increases ubiquitination and degradation of CDK9 by Skp2, an E3 ligase. Notably, combination of US Food and Drug Administration-approved ALK and PARP inhibitors markedly reduce tumor …

T1 Signal Intensity Ratio Of The Pancreas As An Imaging Biomarker For The Staging Of Chronic Pancreatitis, Temel Tirkes, Anil K Dasyam, Zarine K Shah, Evan L Fogel, Santhi Swaroop Vege, Liang Li, Shuang Li, Stephanie T Chang, Carlos A Farinas, Joseph R Grajo, Kareem Mawad, Naoki Takahashi, Sudhakar K Venkatesh, Ashley Wachsman, William E Fisher, Christopher E Forsmark, Phil A Hart, Stephen J Pandol, Walter G Park, Stephen K Van Den Eeden, Yunlong Yang, Mark Topazian, Dana K Andersen, Jose Serrano, Darwin L Conwell, Dhiraj Yadav, Consortium For The Study Of Chronic Pancreatitis, Diabetes, Pancreatic Cancer (Cpdpc)

Faculty, Staff and Student Publications

Purpose: Our purpose was to validate the T1 SIR (T1 score) as an imaging biomarker for the staging of CP in a large, multi-institutional, prospective study.

Methods: The prospective study population included 820 participants enrolled in the PROCEED study from nine clinical centers between June 2017 and December 2021. A radiologist at each institution used a standardized method to measure the T1 signal intensity of the pancreas and the reference organs (spleen, paraspinal muscle, liver), which was used to derive respective T1 scores. Participants were stratified according to the seven mechanistic stages of chronic pancreatitis (MSCP 0-6) based on their …

A Retrospective Analysis Of Ebv-Dna Status With The Prognosis Of Lymphoma, Lihua Qiu, Junqi Si, Junnan Kang, Zehui Chen, Rexidan Nuermaimaiti, Zhengzi Qian, Lanfang Li, Shiyong Zhou, Mingjian James You, Huilai Zhang, Chen Tian

Faculty, Staff and Student Publications

Epstein-Barr virus (EBV) infection is proved to be associated with clinicopathology of lymphoma. However, little is known about the relationship between EBV-DNA status after treatment and prognosis. In this study, real-time polymerase chain reaction (PCR) was used for quantitative detection of EBV-DNA load in peripheral blood of all 26,527 patients with lymphoma, and the clinical characteristics and prognosis of 202 patients were retrospectively analysed, including 100 patients with positive EBV-DNA and 102 randomly selected patients with negative EBV-DNA. We found that the average rate of EBV-DNA positivity in lymphomas was 0.376%, and EBV-DNA-positive patients presented higher risk with elevated lactate …

Comprehensive Multiplexed Immune Profiling Of The Ductal Carcinoma In Situ Immune Microenvironment Regarding Subsequent Ipsilateral Invasive Breast Cancer Risk, Mathilde M Almekinders, Tycho Bismeijer, Tapsi Kumar, Fei Yang, Bram Thijssen, Rianne Van Der Linden, Charlotte Van Rooijen, Shiva Vonk, Baohua Sun, Edwin R Parra Cuentas, Ignacio I Wistuba, Savitri Krishnamurthy, Lindy L Visser, Iris M Seignette, Ingrid Hofland, Joyce Sanders, Annegien Broeks, Jason K Love, Brian Menegaz, Lodewyk Wessels, Alastair M Thompson, Karin E De Visser, Erik Hooijberg, Esther Lips, Andrew Futreal, Jelle Wesseling

Faculty, Staff and Student Publications

Background: Ductal carcinoma in situ (DCIS) is treated to prevent subsequent ipsilateral invasive breast cancer (iIBC). However, many DCIS lesions will never become invasive. To prevent overtreatment, we need to distinguish harmless from potentially hazardous DCIS. We investigated whether the immune microenvironment (IME) in DCIS correlates with transition to iIBC.

Methods: Patients were derived from a Dutch population-based cohort of 10,090 women with pure DCIS with a median follow-up time of 12 years. Density, composition and proximity to the closest DCIS cell of CD20+ B-cells, CD3+CD8+ T-cells, CD3+CD8- T-cells, CD3+FOXP3+ regulatory T-cells, CD68+ cells, and CD8+Ki67+ T-cells was assessed with …

Integrated Imaging And Molecular Analysis To Decipher Tumor Microenvironment In The Era Of Immunotherapy, Jia Wu, Aaron T Mayer, Ruijiang Li

Faculty, Staff and Student Publications

Radiological imaging is an integral component of cancer care, including diagnosis, staging, and treatment response monitoring. It contains rich information about tumor phenotypes that are governed not only by cancer cellintrinsic biological processes but also by the tumor microenvironment, such as the composition and function of tumor-infiltrating immune cells. By analyzing the radiological scans using a quantitative radiomics approach, robust relations between specific imaging and molecular phenotypes can be established. Indeed, a number of studies have demonstrated the feasibility of radiogenomics for predicting intrinsic molecular subtypes and gene expression signatures in breast cancer based on MRI. In parallel, promising results …

Changes In Apparent Diffusion Coefficient (Adc) In Serial Weekly Mri During Radiotherapy In Patients With Head And Neck Cancer: Results From The Predict-Hn Study, Sweet Ping Ng, Carlos E Cardenas, Houda Bahig, Baher Elgohari, Jihong Wang, Jason M Johnson, Amy C Moreno, Shalin J Shah, Adam S Garden, Jack Phan, G Brandon Gunn, Steven J Frank, Yao Ding, Lumine Na, Ying Yuan, Diana Urbauer, Abdallah S R Mohamed, David I Rosenthal, William H Morrison, Michael P Macmanus, Clifton D Fuller

Faculty, Staff and Student Publications

Background: The PREDICT-HN study aimed to systematically assess the kinetics of imaging MR biomarkers during head and neck radiotherapy.

Methods: Patients with intact squamous cell carcinoma of the head and neck were enrolled. Pre-, during, and post-treatment MRI were obtained. Serial GTV and ADC measurements were recorded. The correlation between each feature and the GTV was calculated using Spearman’s correlation coefficient. The linear mixed model was used to evaluate the change in GTV over time.

Results: A total of 41 patients completed the study. The majority (76%) had oropharyngeal cancer. A total of 36 patients had intact primary tumours that …

Modeling The Prognostic Impact Of Circulating Tumor Cells Enumeration In Metastatic Breast Cancer For Clinical Trial Design Simulation, Lorenzo Gerratana, Jean-Yves Pierga, James M Reuben, Andrew A Davis, Firas H Wehbe, Luc Dirix, Tanja Fehm, Franco Nolé, Rafael Gisbert-Criado, Dimitrios Mavroudis, Salvatore Grisanti, Jose A Garcia-Saenz, Justin Stebbing, Carlos Caldas, Paola Gazzaniga, Luis Manso, Rita Zamarchi, Marta Bonotto, Angela Fernandez De Lascoiti, Leticia De Mattos-Arruda, Michail Ignatiadis, Maria-Teresa Sandri, Daniele Generali, Carmine De Angelis, Sarah-Jane Dawson, Wolfgang Janni, Vicente Carañana, Sabine Riethdorf, Erich-Franz Solomayer, Fabio Puglisi, Mario Giuliano, Klaus Pantel, François-Clément Bidard, Massimo Cristofanilli

Faculty, Staff and Student Publications

Despite the strong prognostic stratification of circulating tumor cells (CTCs) enumeration in metastatic breast cancer (MBC), current clinical trials usually do not include a baseline CTCs in their design. This study aimed to generate a classifier for CTCs prognostic simulation in existing datasets for hypothesis generation in patients with MBC. A K-nearest neighbor machine learning algorithm was trained on a pooled dataset comprising 2436 individual MBC patients from the European Pooled Analysis Consortium and the MD Anderson Cancer Center to identify patients likely to have CTCs ≥ 5/7 mL blood (StageIVaggressive vs StageIVindolent). The model had a 65.1% accuracy and …

Pathological Response And Immune Biomarker Assessment In Non-Small-Cell Lung Carcinoma Receiving Neoadjuvant Immune Checkpoint Inhibitors, Frank Rojas, Edwin Roger Parra, Ignacio Ivan Wistuba, Cara Haymaker, Luisa Maren Solis Soto

Faculty, Staff and Student Publications

Lung cancer is the leading cause of cancer incidence and mortality worldwide. Adjuvant and neoadjuvant chemotherapy have been used in the perioperative setting of non-small-cell carcinoma (NSCLC); however, the five-year survival rate only improves by about 5%. Neoadjuvant treatment with immune checkpoint inhibitors (ICIs) has become significant due to improved survival in advanced NSCLC patients treated with immunotherapy agents. The assessment of pathology response has been proposed as a surrogate indicator of the benefits of neaodjuvant therapy. An outline of recommendations has been published by the International Association for the Study of Lung Cancer (IASLC) for the evaluation of pathologic …

Distinct Immune Gene Programs Associated With Host Tumor Immunity, Neoadjuvant Chemotherapy, And Chemoimmunotherapy In Resectable Nsclc, Pedro Rocha, Jiexin Zhang, Raquel Laza-Briviesca, Alberto Cruz-Bermúdez, Neus Bota-Rabassedas, Beatriz Sanchez-Espiridon, Katsuhiro Yoshimura, Carmen Behrens, Wei Lu, Ximing Tang, Apar Pataer, Edwin R Parra, Cara Haymaker, Junya Fujimoto, Stephen G Swisher, John V Heymach, Don L Gibbons, J Jack Lee, Boris Sepesi, Tina Cascone, Luisa M Solis, Mariano Provencio, Ignacio I Wistuba, Humam Kadara

Faculty, Staff and Student Publications

Purpose: Our understanding of the immunopathology of resectable non-small cell lung cancer (NSCLC) is still limited. Here, we explore immune programs that inform of tumor immunity and response to neoadjuvant chemotherapy and chemoimmunotherapy in localized NSCLC.

Experimental design: Targeted immune gene sequencing using the HTG Precision Immuno-Oncology panel was performed in localized NSCLCs from three cohorts based on treatment: naïve (n = 190), neoadjuvant chemotherapy (n = 38), and neoadjuvant chemoimmunotherapy (n = 21). Tumor immune microenvironment (TIME) phenotypes were based on the location of CD8+ T cells (inflamed, cold, excluded), tumoral PD-L1 expression (<1% and ≥1%), and tumor-infiltrating lymphocytes (TIL). Immune programs and signatures were statistically analyzed on the basis of tumoral PD-L1 expression, immune phenotypes, and pathologic response and were cross-compared across the three cohorts.

Results: PD-L1-positive tumors exhibited increased …

Tumor Immunology And Immunotherapy Of Non-Small-Cell Lung Cancer, Tina Cascone, Jared Fradette, Monika Pradhan, Don L Gibbons

Faculty, Staff and Student Publications

Historically, non-small-cell lung cancer (NSCLC) has been regarded as a nonimmunogenic tumor; however, recent studies have shown that NSCLCs are among the most responsive cancers to monoclonal antibody immune checkpoint inhibitors (ICIs). ICIs have dramatically improved clinical outcomes for a subset of patients (∼20%) with locally advanced and metastatic NSCLC, and they have also demonstrated promise as neoadjuvant therapy for early-stage resectable disease. Nevertheless, the majority of patients with NSCLC are refractory to ICIs for reasons that are poorly understood. Thus, major questions are: how do we initially identify the patients most likely to derive significant clinical benefit from these …

Landscape Of Notch1 Mutations And Co-Occurring Biomarker Alterations In Chronic Lymphocytic Leukemia, Fatima Zahra Jelloul, Richard Yang, Sofia Garces, Rashmi Kanagal-Shamanna, Chi Y Ok, Sanam Loghavi, Mark J Routbort, Zhuang Zuo, C Cameron Yin, Kristen Floyd, Roland L Bassett, William Wierda, Nitin Jain, Philip Thompson, Rajyalakshmi Luthra, L Jeffrey Medeiros, Keyur P Patel

Faculty, Staff and Student Publications

NOTCH1 is one of the most frequently mutated genes in chronic lymphocytic leukemia and has emerged as a marker of poor prognosis. In addition to coding NOTCH1 mutations involving exon 34, non-coding NOTCH1 mutations involving the 3' UTR have been described in a limited number of chronic lymphocytic leukemia (CLL) patients and were associated with adverse outcomes. In this study, 1574 CLL patients were assessed using targeted sequencing with a 29 gene panel and the results were correlated with prognostic characteristics. NOTCH1 mutations were detected in 252 (16%) patients, including both coding (220/252, 14%), non-coding (24/252, 1.5%) and a mixture …

Ndrg1 In Aggressive Breast Cancer Progression And Brain Metastasis, Emilly S Villodre, Xiaoding Hu, Bedrich L Eckhardt, Richard Larson, Lei Huo, Ester C Yoon, Yun Gong, Juhee Song, Shuying Liu, Naoto T Ueno, Savitri Krishnamurthy, Stefan Pusch, Debu Tripathy, Wendy A Woodward, Bisrat G Debeb

Faculty, Staff and Student Publications

BACKGROUND: N-Myc downstream regulated gene 1 (NDRG1) suppresses metastasis in many human malignancies, including breast cancer, yet has been associated with worse survival in patients with inflammatory breast cancer. The role of NDRG1 in the pathobiology of aggressive breast cancers remains elusive.

METHODS: To study the role of NDRG1 in tumor growth and brain metastasis in vivo, we transplanted cells into cleared mammary fat pads or injected them in tail veins of SCID/Beige mice (n = 7-10 per group). NDRG1 protein expression in patient breast tumors (n = 216) was assessed by immunohistochemical staining. Kaplan-Meier method with 2-sided log-rank test …

Fungal Mycobiome Drives Il-33 Secretion And Type 2 Immunity In Pancreatic Cancer, Aftab Alam, Eric Levanduski, Parker Denz, Helena Solleiro Villavicencio, Maulasri Bhatta, Lamees Alhorebi, Yali Zhang, Eduardo Cortes Gomez, Brian Morreale, Sharon Senchanthisai, Jun Li, Steven G Turowski, Sandra Sexton, Sheila Jani Sait, Prashant K Singh, Jianmin Wang, Anirban Maitra, Pawel Kalinski, Ronald A Depinho, Huamin Wang, Wenting Liao, Scott I Abrams, Brahm H Segal, Prasenjit Dey

Faculty, Staff and Student Publications

TH2 cells and innate lymphoid cells 2 (ILC2) can stimulate tumor growth by secreting pro-tumorigenic cytokines such as interleukin-4 (IL-4), IL-5, and IL-13. However, the mechanisms by which type 2 immune cells traffic to the tumor microenvironment are unknown. Here, we show that oncogenic KrasG12D increases IL-33 expression in pancreatic ductal adenocarcinoma (PDAC) cells, which recruits and activates TH2 and ILC2 cells. Correspondingly, cancer-cell-specific deletion of IL-33 reduces TH2 and ILC2 recruitment and promotes tumor regression. Unexpectedly, IL-33 secretion is dependent on the intratumoral fungal mycobiome. Genetic deletion of IL-33 or anti-fungal treatment decreases TH2 and ILC2 infiltration and increases …

Evaluation Of Programmed Death Ligand 1 Expression In Cytology To Determine Eligibility For Immune Checkpoint Inhibitor Therapy In Patients With Head And Neck Squamous Cell Carcinoma, Zhonghua Liu, Michelle Williams, John Stewart, Bonnie S Glisson, Clifton Fuller, Sinchita Roy-Chowdhuri

Faculty, Staff and Student Publications

Background: Immune checkpoint inhibitors targeting the programmed cell death protein 1 (PD-1)/programmed cell death ligand 1 (PD-L1) pathway have recently emerged as a frontline treatment for head and neck squamous cell carcinoma (HNSCC). The evaluation of PD-L1 expression by immunohistochemistry in histologic samples is used to determine the eligibility of patients with HNSCC for immunotherapy. Patients with newly diagnosed HNSCC are frequently diagnosed by fine-needle aspiration (FNA) of lymph nodes with metastatic disease. However, the evaluation of PD-L1 expression with the proposed combined positive score (CPS) has not been well established in cytology specimens.

Methods: This study retrospectively identified 21 …

Clinical And Molecular Characterization Of Pole Mutations As Predictive Biomarkers Of Response To Immune Checkpoint Inhibitors In Advanced Cancers, Benjamin Garmezy, Jinesh Gheeya, Heather Y Lin, Yuefan Huang, Taebeom Kim, Xianli Jiang, Kyaw Z Thein, Patrick G Pilié, Fadl Zeineddine, Wanlin Wang, Kenna R Shaw, Jordi Rodon, John Paul Shen, Ying Yuan, Funda Meric-Bernstam, Ken Chen, Timothy A Yap

Faculty, Staff and Student Publications

Purpose: DNA polymerase epsilon is critical to DNA proofreading and replication. Mutations in POLE have been associated with hypermutated tumors and antitumor response to immune checkpoint inhibitor (ICI) therapy. We present a clinicopathologic analysis of patients with advanced cancers harboring POLE mutations, the pattern of co-occurring mutations, and their response to ICI therapy within the context of mutation pathogenicity.

Methods: We conducted a retrospective analysis of next-generation sequencing data at MD Anderson Cancer Center to identify patient tumors with POLE mutations and their co-occurring mutations. The pathogenicity of each mutation was annotated using InterVar and ClinVar. Differences in therapeutic response …

Rapid Induction Of The Unfolded Protein Response And Apoptosis By Estrogen Mimic Ttc-352 For The Treatment Of Endocrine-Resistant Breast Cancer, Balkees Abderrahman, Philipp Y Maximov, Ramona F Curpan, Sean W Fanning, Jay S Hanspal, Ping Fan, Charles E Foulds, Yue Chen, Anna Malovannaya, Antrix Jain, Rui Xiong, Geoffrey L Greene, Debra A Tonetti, Gregory R J Thatcher, V Craig Jordan

Faculty, Staff and Students Publications

Patients with long-term estrogen-deprived breast cancer (BC), after resistance to tamoxifen or aromatase inhibitors develops, can experience tumor regression when treated with estrogens. Estrogen’s anti-tumor effect is attributed to apoptosis via the estrogen receptor (ER). Estrogen treatment can have unpleasant gynecological and non-gynecological adverse events thus the development of safer estrogenic agents remains a clinical priority. Here, we study synthetic selective estrogen mimics (SEMs) BMI-135 and TTC-352, and the naturally-occurring estrogen estetrol (E4), which are proposed as safer estrogenic agents compared to 17β-estradiol (E2), for the treatment of endocrine-resistant BC. TTC-352 and E4 are being evaluated in BC clinical trials. …

Aav-Crispr Gene Editing Is Negated By Pre-Existing Immunity To Cas9, Ang Li, Mark R Tanner, Ciaran M Lee, Ayrea E Hurley, Marco De Giorgi, Kelsey E Jarrett, Timothy H Davis, Alexandria M Doerfler, Gang Bao, Christine Beeton, William R Lagor

Faculty, Staff and Students Publications

Adeno-associated viral (AAV) vectors are a leading candidate for the delivery of CRISPR-Cas9 for therapeutic genome editing in vivo. However, AAV-based delivery involves persistent expression of the Cas9 nuclease, a bacterial protein. Recent studies indicate a high prevalence of neutralizing antibodies and T cells specific to the commonly used Cas9 orthologs from Streptococcus pyogenes (SpCas9) and Staphylococcus aureus (SaCas9) in humans. We tested in a mouse model whether pre-existing immunity to SaCas9 would pose a barrier to liver genome editing with AAV packaging CRISPR-Cas9. Although efficient genome editing occurred in mouse liver with pre-existing SaCas9 immunity, this was accompanied by …