WIF1 and colorectal carcinoma: To this end, four genes were selected known to have an antagonistic effect on the Wnt-pathway, which have been described before to be frequently methylated in CRC; Secreted Frizzled-Related Protein-2 (SFRP2), Wnt Inhibitory Factor-1 (WIF-1), Dickkopf-3 (DKK3) and SRY-Box-17 (SOX17) [17-24].