FTO and melanoma: Wang et al. reported that depletion of METTL3/14 enhanced infiltration and cytokines secretion of CTL, augmenting anti-PD-1 therapy efficacy of CRC in vivo, through m6A/YTHDF2/STAT1/IRF1 axis.397 However, METTL14 could sensitize cholangiocarcinoma to ICB via YTHDF1-mediated degradation of SIAH2 mRNA.398 Knockdown of YTHDF1 enhances cross-presentation of DCs to CD8 + T cells by suppressing cathepsins expression, further increased IFN-γ secretion of T cells upregulates PD-L1 level in tumor cells.399 FTO was identified to negatively regulate ICB therapeutic efficacy in melanoma.