CDKN2A and lung cancer: Methylation of p16 and many other genes in lung cancer is now widely documented and genome-wide profiling has revealed subgroups of tumors with specific patterns (Tsou et al., 2007; Anglim et al., 2008; Carvalho et al., 2012; Kwon et al., 2012; Lockwood et al., 2012; Selamat et al., 2012; Shinjo et al., 2012; Walter et al., 2012; Wilkerson et al., 2012; Heller et al., 2013; Park et al., 2013).