One of the first papers comparing the tumor transcriptome at baseline of melanoma patients undergoing anti-PD-1 therapy described an “innate anti-PD-1 resistance signature” that comprised genes involved in the mesenchymal transition (AXL, ROR2, WNT5A, LOXL2, TWIST2, TAGLN, FAP), immunosuppression (IL10, VEGFA, VEGFC) and monocyte and macrophage chemotaxis (CCL2, CCL7, CCL8, and CCL13) in non-responder patients (80). This evidence concerns the gene PDCD1 and melanoma.