NBN and cancer: Mutations in HR genes can cause genome instability and predisposition to cancer; for example, ataxia telangiectasia, Nijmegen breakage syndrome, and Bloom syndrome are caused by mutations in ATM, NBN, and BLM, respectively, and are associated with pleiotropic cancer susceptibility (Renwick et al, 2006; Belhadj et al, 2023; German, 1997).