BRCA1 and carcinosarcoma: Second, we utilized a different induction method than in previous studies; for example, Kumar et al. [13] used WAP-Cre directed expression of MMTV-T121 to suppress Rbf, and when combined with Trp53 and Brca1 inactivation mice developed carcinosarcomas that variably expressed basal/myoepithelial lineage markers (Keratins-5, -14) and epithelial-to-mesenchymal transition (EMT) in addition to adenocarcinoma tumors.