Indeed, the group that developed cutaneous irAEs, including lichen planus, had significantly prolonged OS compared with the group that did not develop cutaneous irAEs in patients treated with anti-PD1 Abs [52], suggesting that lichen planus could be a cutaneous manifestation that predicts a good prognosis in melanoma patients treated with anti-PD1 Abs. This evidence concerns the gene PDCD1 and melanoma.