A key feature of NB is that it is a uniform p53 wild-type at diagnosis with intact intrinsic and extrinsic apoptotic mechanisms; direct inactivation of p53 mutations, which are rare, regardless of the stage of treatment, suggests that NBs feature an innate requirement for a baseline p53 activity (Kim & Shohet, 2009). Here, TP53 is linked to Nijmegen breakage syndrome.