When we analyzed data from two small cohorts of previously reported patients with melanoma treated with immune checkpoint therapy [24, 25], we found nearly all melanoma specimens (98.5%) in both immune check point inhibitor-treated cohorts expressed some full-length PD-L1 (ipilimumab n = 40, PD-1 blocker n = 28), which was comparable to that (98.9%) in the cohort of cutaneous melanoma specimens in the TCGA (Supplemental Fig. 2d–e). This evidence concerns the gene PDCD1 and melanoma.