PARP1 and invasive ductal breast carcinoma: The adjacent normal breast tissues were negative for expression of PARP1, BRCA1 and BRCA2 (Figure 3A–3C); Negative expression of PARP1, BRCA1 and BRCA2 in the same breast invasive ductal carcinoma (Stage IIa, TNM: T2N0M0) were showed as Figure 3D–3F.