CTLA4 and metastatic melanoma: A total of 282 whole exome sequencing data from three cohorts of patients who received immune checkpoint blockade immunotherapy were analyzed, including Anti-PDL1 treated in metastatic urothelial cancer (N = 216), anti-PD1 treated metastatic melanoma (N = 26), and anti-CTLA4 treated metastatic melanoma (N = 39).