The ApccKOSmad4cKO model will provide new genetic information for prostate cancer development, particularly in the basaloid and squamous differentiated cancers, and will serve as a model of castration resistance and potentially for a sub-population of prostate cancer patients whose tumors involve some combination of aberrant Wnt, TGFβ, and BMP signaling. This evidence concerns the gene TGFB1 and prostate carcinoma.