Accumulating data indicates that BRCA1 regulates stem/progenitor cell fate in the breast (Liu et al. 2008; Ribeiro-Silva et al. 2005), and loss of function or suppressed BRCA1 expression may lead to dysregulated stem cell self-renewal or differentiation leading to basal-type breast carcinomas (Liu et al. 2008). The gene discussed is BRCA1; the disease is breast carcinoma.