In the current study, we modeled postmenopausal basal-like breast cancer in the context of different p53 gene dosage by injecting MMTV-Wnt-1 mammary tumor cells that were either p53+/+ or p53+/− into the mammary fat pads of ovariectomized female C57BL/6 mice. This evidence concerns the gene WNT1 and breast carcinoma.