TFPI2 downregulation, largely due to promoter hypermethylation, is common in many cancers, including glioma, lung, breast, melanoma, colorectal, pancreatic, liver, gastric, oral, thyroid, cervical, prostate, and bladder cancers [14,15,16,22,154,155,156,157]. This evidence concerns the gene TFPI2 and melanoma.