CTLA4 and colonic neoplasm: In addition, as microsatellite instability (MSI) is one biomarker for response to PD-L1 and CTLA-4 immunotherapies and good prognosis in colon cancer (28–31), we explored the frequency of MSI to predict the number of AA patients that could benefit from these immunotherapies that appear to be effective in CA colon cancer patients (28–31).