Oncoproteins, such as activated Ras and SV40 T antigen, stimulate the RAD51 promoter and RAD51 expression is positively regulated by the EGR1 transcription factor [32], while p53, which is mutated or functionally inactivated in the majority of cancers, binds to and represses the RAD51 promoter [33]. The gene discussed is EGR1; the disease is cancer.