BRCA1 and Hereditary breast cancer: Germline mutations of BARD1 have also been implicated as pathogenic lesions in some families with hereditary breast cancer,29 and conditional inactivation of either Brca1 or Bard1 in mice generates mammary carcinomas that closely resemble the basal‐like, triple‐negative breast cancers that arise in human BRCA1 mutation carriers.30, 31