It is known that PD-L1 in many tumors has high expression, including lung cancer, colorectal cancer, gastric cancer, melanoma, leukemia, stromal tumor, multiple myeloma, esophageal, ovarian, pancreatic, renal cell carcinoma, oral squamous cell carcinoma, and nasopharyngeal carcinoma [11–18]. This evidence concerns the gene CD274 and melanoma.