Having thoroughly evaluated the technical aspects of the Oncomine TCRB-LR assay, we next applied the assay to evaluate TCR convergence as a predictive biomarker for response to CTLA-4 blockade in a cohort of 22 individuals with RECIST graded response annotations (11 responders, 11 non-responders) representing three major cancer types: clear cell adenocarcinoma (two responders, zero non-responder), melanoma (seven responders, six non-responders) and prostate cancer (two responders, four non-responders). The gene discussed is CTLA4; the disease is Familial prostate cancer.