APC and cancer: In the present study, the identification of CGI methylation of the Wnt signalling pathway regulatory genes APC, SFRP1, SFRP2, SFRP4, SFRP5 and WIF1 as significant features contributing to the discrimination of tumours from normal mucosa, cancer mucosa from non-cancer mucosa and polyp mucosa from neoplasia-free mucosa is consistent with this hypothesis.