One explanation as to why activating CTNNB1 mutations are rare in CRC is due to the high levels of E-cadherin expression in the colonic epithelium that serves to sequester β-catenin to the cell membrane and therefore limits the transforming properties of CTNNB1 mutations in CRC compared to APC mutations [9]. The gene discussed is CTNNB1; the disease is colorectal carcinoma.