BRCA1 and breast carcinoma: Based on the phenotype of the Tcf1−/− mice demonstrating mammary adenomas in the absence of Tcf1, it is possible that the decrease of TCF7 in basal/myoepithelial cells of BRCA1 mutation carriers may play a role in their higher risk of breast cancer, especially predisposing them to basal/triple-negative tumors.