CASP3 and cancer: To confirm the facilitative role of caspase-3 in oncogene-mediated transformation, caspase-3 deficient (Casp3 KO) mice [23] were crossed to MMTV-PyMT transgenic mice predisposed to malignant mammary adenocarcinoma as a result of mammary gland-directed expression of a Pymt oncogene [24].