CDKN2A and cancer: Patients with diseases such as cancer show not only nucleotide deletions and mutations (Pollock et al., 2001; Attwooll et al., 2002; Taniai et al., 2002; Fombonne et al., 2005; Hsieh et al., 2007) but also nucleotide methylation (Herman et al., 1996; Narimatsu et al., 2004; Amatya et al., 2005) in the promoter regions of p53 and p16INK4a.