APC and lung cancer: As the epigenetic silencing of key tumor suppressor genes, such as APC and p16INK4A, is a common event in lung carcinogenesis (Takai et al., 2001; Sano et al., 2007; Brock et al., 2008; Kusakabe et al., 2010) and miRNA expression is altered in lung cancer (Yanaihara et al., 2006), some miRNAs are thought to be silenced by DNA methylation or histone modification in lung cancer.