Interesting data on tumor suppressor gene promoter hypermethylation in RASSF1A, DAPK1, and the p16INK4a CpG gene island were presented by Ovchinnikov et al. [70] in a study on salivary DNA from 143 head-and-neck-cancer patients and 31 healthy non-smoker controls. This evidence concerns the gene DAPK1 and head and neck cancer.