Moreover, we detected that PD-L1 expression was positively correlated with some cuproptosis-related genes (CDKN2A, FDX1, LIPT1, and MTF1), but negatively correlated with other cuproptosis-related genes (ATP7B, DLST, and PDHA1) in an analysis of 470 melanoma patients (Supplementary Figure S2C). Here, MTF1 is linked to melanoma.