BRCA1 and neoplasm: Thus, considering only the 38 high grade serous/undifferentiated tumours in our study, 18 (18/38, 47%) had loss of BRCA1 either through genetic or epigenetic events, three (3/38, 8%) carried germline or somatic BRCA2 mutations, 12 (12/38, 32%) had preservation of BRCA1 expression and no mutations in BRCA1 or BRCA2, and the remaining five tumors (5/38, 13%) were equivocal for BRCA1 loss and did not have BRCA2 mutations.