The breast cancer suppressor BRCA2 and the RAD51 paralog complexes, either RAD51B–RAD51C–RAD51D–XRCC2 (BCDX2) or RAD51C–XRCC3 (CX3) then help load RAD51 on the resected DNA to form a filament, displacing RPA. This evidence concerns the gene RAD51 and breast cancer.