As such, cells derived from ataxia-telangiectasia-like disease (ATLD) and Nijmegen breakage syndrome (NBS) patients that express mutant forms of either MRE11 or NBS1, respectively, display greatly reduced ATM activation and a predisposition to cancer development (Uziel et al., 2003). The gene discussed is MRE11; the disease is Nijmegen breakage syndrome.