BRCA1 and breast cancer: Notably, error‐prone DSB repair, such as microhomology‐mediated end joining, associates with BC/OC risk as previously shown for cells from BRCA1, BRCA2, and PALB2 mutation carriers as well as in a case–control format independently of the individual risk genotype (Keimling et al., 2012, 2011; Obermeier et al., 2016).