Complementarily, Brca1F/F Trp53F/F Krt14-Cre mice develop mammary tumors (Liu et al., 2007) (designated as BRCA1-null tumors) which mimic basal-like breast cancers and were ER-/PR-/HER- (Figure 1—figure supplement 1A). Here, ESR1 is linked to breast carcinoma.