ESR2 and colorectal carcinoma: Moreover, whereas both ERα and ERβ deficiency have been associated with enhanced intestinal neoplasia in mice carrying APC mutations, only ERα deficiency was associated with activation of WNT/β-catenin signaling [35], and functional studies in CRC cells have demonstrated antiproliferative and antitumorigenic effects of ERβ overexpression, despite a functional link to increased cyclin D1 levels [36].