APC and colorectal cancer: In colorectal cancer, loss-of-function mutations of the APC gene led to stabilization and accumulation of β-catenin and constitutive transcriptional activation of Wnt/β-catenin target genes through TCF/LEF:β-catenin activity (Kinzler et al., 1991; Nishisho et al., 1991; Su et al., 1993; Korinek et al., 1997).