BRCA1 and breast cancer: As demonstrated in Table 2, 35.0% (35/100) breast cancer tissues were positive for PARP1 expression in the nuclei (Figure 3H); 34% (34/100) breast cancer tissues were positive for BRCA1 expression in both the nuclei and cytoplasm (Figure 3I), 33% (33/100) breast cancer tissues were positive for BRCA2 expression in both the nuclei and cytoplasm (Figure 3G).