MYC and breast cancer: To further corroborate our findings from the WB1P and WB1P-Myc tumor models, we used somatic engineering33 to induce mammary tumors in Brca1F/F;Trp53F/F (B1P) and Brca1F/F;Trp53F/F;Col1a1invCAG-Myc-IRES-Luc/+ (B1P-Myc) mice via intraductal injection of a Cre-encoding lentivirus.