To evaluate the specificity of the effects of MPA on oviductal tumorigenesis, we tested the effects of MPA in a GEMM of colon cancer based on the conditional somatic inactivation of the Apc and Trp53 tumor suppressor genes and activation of Kras (AKP mice) in the colonic epithelium [14]. This evidence concerns the gene KRAS and malignant colon neoplasm.