Large-scale genome-wide sequencings performed within the last decade suggest that up to 10% of pediatric malignancies are related to a genetic predisposition syndrome.1 Among those malignancies, medulloblastomas (MB) are rare embryonal tumors developing from various cerebellar embryonal progenitors, consensually categorized in 4 different molecular entities defined according to their cell of origin and their main oncogenic drivers, ie WNT, SHH TP53-wildtype, SHH TP53-mutant, and non-WNT/non-SHH2 (including MB-group 3 and MB-group 4). The gene discussed is TP53; the disease is medulloblastoma.