BRCA1 and breast cancer: A PV in BRCA1 and/or BRCA2 with LOH of the wild-type allele was identified in three out of 23 HRD tumors, providing an explanation for the observed HRD phenotype (i.e., BC-01 (BRCA2 PV), BC-44 (BRCA1 PV), and BC-45 (BRCA1 and BRCA2 PV), Fig. 2, Suppl.