BRCA1 and breast cancer: The majority of TNBCs can be characterized as basal‐like4 and have an expression profile enriched with genes involved in DNA damage checkpoint response.5, 6 More than 80% of breast cancer patients with a hereditary BRCA1 mutation are assigned to TNBC subtype.7 Some sporadic TNBCs also show similar characteristics with BRCA1‐mutant tumors.