The importance of RAD51 in DNA DSB repair is illustrated by studies showing that increased expression of RAD51 and other HR-associated genes in tumor cells is associated with resistance to radiotherapies or chemotherapies that induce DNA damage (13, 14), implying that targeting RAD51 may improve the efficacy of DNA-damaging agents such as irradiation or chemotherapy. This evidence concerns the gene RAD51 and neoplasm.