HR operates during the S and G2 phases of the cell cycle and relies on many proteins including BRCA1 and BRCA2, proteins of the MNR complex (MRE11/RAD50/NBS1), CtIP, MRE11, RAD51, ATM, H2AX, PALB2, RPA, RAD52 and proteins of the Fanconi anemia pathway [8, 9]. The gene discussed is ATM; the disease is Fanconi anemia.