BRCA2 and breast cancer: One study has investigated the association of BRCA2 gene mutation and the deficit in the DNA repriming where ZRANB3 and other repairing factors are depleted; they found that these cells are having increased risk of DNA instability in the form of chromatid breaks (CTB) after radiation in patient with breast cancer suggesting the association of this defect to play role in the tumor suppression and response to treatment [36].