Multiple studies have examined that down-regulation of P16 gene expression and its association with promoter hypermethylation is common in NPC (Mäkitie et al., 2003; Hutajulu et al., 2011; Lee and Pausova, 2013; Shao et al., 2014; Nawaz, 2015a; Jiang et al., 2016). The gene discussed is CDKN2A; the disease is nasopharyngeal carcinoma.