CHEK1 and Fanconi anemia: HRR alterations involve Fanconi anemia genes (PALB2, FANCA, FANCL, FANCI, FANCC), core RAD genes (RAD50, RAD51, RAD51B, RAD51C) as well as DNA damage response genes (ATM, ATR, CHEK1, CHEK2) (10).