MRE11 and Nijmegen breakage syndrome: In humans, germline hypomorphic mutations in MRE11, NBS1, or RAD50 are associated with ataxia telangiectasia-like disorder (ATLD), Nijmegen breakage syndrome (NBS), and NBS-like disorder (NBSLD), respectively, which are characterized by cellular radiosensitivity, immune deficiency and cancer predisposition [33].