Analysis of DDR mutations in BC based on multiple studies encompassing over 5,000 cases collectively, has revealed that ATM and ATR were the most common DDR-associated genes besides BRCA1 and BRCA2, with prevalence rates ranging from 2.3−4.2% and 1.3−3.7%, respectively [23, 25, 26]. Here, BRCA2 is linked to breast cancer.