PDCD1 and melanoma: Knockdown of FTO elevated the m6A level in transcripts of several critical melanoma-promoting genes, including PD-1, C-X-C motif chemokine receptor 4 (CXCR4), and SOX10, then accelerated RNA decay mediated by YTHDF2, restoring IFN-γ response in vitro and sensitizing anti-PD-1 treatment in vivo [138].