RAD51 and Familial prostate cancer: However, while control (siNEG) cells form Rad51 foci indicative of HR-mediated repair, cells with siRNA-mediated depletion of PALB2 or BARD1 resemble BRCA2-deficient cells and fail to form Rad51 foci, suggesting that PALB2 or BARD1 loss is sufficient to confer HR deficiency in prostate cancer cells (Fig. 2a; Supplementary Fig. 3).