The response to immune checkpoint inhibitor treatment is available in five cancer types—anti-PD1-treated melanoma [20,21,22,23,24], anti-PDL1-treated bladder urothelial cancer and renal cell cancer (ImVigor clinical trial [25], anti-PD1-treated renal cell cancer [26], anti-PD1 treated metastatic gastric cancer [27], and anti-PD1 treated non-small cell lung cancer [28]—from ten published data sets of cancer patients. The gene discussed is PDCD1; the disease is bladder transitional cell carcinoma.