Numerous successful clinical trials have led to a great number of FDA approvals for PD-1/PD-L1 blockade therapy in a spectrum of different tumour types: melanoma, non-small cell lung cancer, urothelial carcinoma, classic Hodgkin lymphoma, renal cell carcinoma, Merkel cell carcinoma, hepatocellular carcinoma, gastric carcinomas, and head and neck squamous cell carcinoma. Here, PDCD1 is linked to neoplasm.