We generated Myc;Ptenfl (Rosa;LSL-Myc/LSL-MycPten;flox/floxBlg-Cre) mice by crossing the RosaLSL-Myc/LSL-Myc mice that express two copies of Cre-inducible Myc driven by the Rosa26 promoter, which results in constitutive MYC expression at about twofold above normal mammary gland32, relevant to the upregulation of MYC in CNA breast cancer (Fig.  1B) with Ptenflox/flox mice for Cre-inducible knockout of Pten33 (Fig. 1E). This evidence concerns the gene MYC and breast cancer.