TP53 and medulloblastoma: To explore whether differences in drug response between TP53-wildtype and TP53-mutated SHH medulloblastoma cells could be recapitulated in vitro, we utilised ONS76 cells (TP53-wildtype) and a genetically modified ONS76 cell line harbouring a dominant negative p53 mutation (TP53-mutant; ONS76 dnp53)26.