BRCA1 and breast carcinoma: Interestingly, from clinical and experimental data there is an emerging evidence that familial breast cancers, including BRCA1 and its related forms, could be estrogen-sensitive and interactions between BRCA1 gene expression and estrogens have been reported (Zheng et al., 2001; Lindgren et al., 2002; Venkitaraman, 2002).