CDX2 and colorectal carcinoma: We next used MiMouse to credential the fidelity of two colorectal carcinoma GEMM models using tamoxifen-inducible Cre to inactivate one copy of Apc in the presence of activated Kras (AK) ± altered Trp53 (AKP) in epithelial cells of the colorectum (via the Cdx2 promoter; ref. 45).