These include the two HR factors CtIP and RAD51, the early transductors of RS signaling ATR (ataxia telangiectasia and Rad3-related) and ATRIP (ATR interacting protein), and the Fanconi anemia (FA) protein FANCD2 (Fanconi anemia group D2 protein) [23]. This evidence concerns the gene ATR and Fanconi anemia.