CCNA1 and head and neck squamous cell carcinoma: According to Carvalho et al., salivary DNA promoter hypermethylation analyses facilitate the early diagnosis of HNSCC, and several hypermethylated genes (DAPK, DCC, MINT-31, TIMP-3, p16, MGMT, and CCNA1) have already been identified in salivary rinse samples [10–12].