Interestingly, previous studies have shown that methylation of cytosine–phosphorothioate–guanine islands located in the promoter region of TFPI2 gene reduces or abolishes expression of TFPI2 in cancers such as oral squamous cell carcinoma [21], diffuse B-cell lymphoma [22], hepatocellular, and pancreatic cancer. Here, TFPI2 is linked to oral cavity squamous cell carcinoma.