Of note, some tumors that stain positively for PD-L1 by IHC (including melanoma, NSCLC, renal cell carcinoma, colorectal carcinoma, and castration-resistant prostate cancer) are insensitive to ICBs, suggesting that PD-L1 alone is not a reliable predictor of clinical response [43]. This evidence concerns the gene CD274 and hereditary clear cell renal cell carcinoma.