Notably, lobular breast cancer (LBC) is less common as a proportion of breast cancers in women with BRCA1 PGVs compared to women without BRCA1 PGVs [3–6] As the main pathway to breast cancer is from basal progenitor cells leading to the predominant ductal triple negative breast cancer, this route excludes the predominantly estrogen receptor positive lobular cancer. Here, BRCA1 is linked to breast carcinoma.