PDCD1 and melanoma: Knockdown of FTO increases m6A methylation of PD-1 in melanoma cells, while deletion of ALKBH5 (the ‘eraser’ of m6A) enriches the 3’UTR region of PD-L1 mRNA with m6A modifications, thereby promoting the degradation of PD-1 and PD-L1 in a YTHDF2-dependent manner (68, 69).