CXCR4 and melanoma: FTO enhances the stability of crucial immunotherapy resistance and pro-tumorigenic melanoma cell-intrinsic genes, including programmed cell death 1 (PDCD1), CXC-chemokine receptor 4 (CXCR4), and SRY-box 10 (SOX10), which facilitates melanoma progression and decreases the response to anti-PD-1 blockade [109].