Numerous clinical studies have shown that PD-L1 expression on tumor cells or in the tumor microenvironment is positively correlated with the response rate to anti-PD-1/PD-L1 therapy (Patel and Kurzrock 2015; Grigg and Rizvi 2016), suggesting that patients with high immune checkpoint expression may benefit from immunotherapy. This evidence concerns the gene PDCD1 and neoplasm.