BRCA1 and breast cancer: Significantly increased Ezh2 expression in female BRCA1-deficient K14cre; Brca1F/F; Trp53F/F (KB1P) mouse mammary tumors compared to BRCA1-proficient K14cre; Trp53F/F (KP) mammary tumors was further corroborated by RNA sequencing of tumor tissue (p = 0.0156; Fig. 1A, right panel).