ATRX and neoplasm: Although frequently mutated genes across the cohort were uncommon, these were seen in both the patient tumours and cell models including those in TP53 (40% patient tumours, 75% cell lines, 67% PDX models), ATRX (35% patient tumours, 35% cell lines, 67% PDX models) and RB1 (10% patient tumours, 25% cell lines, 0% PDX models) (Fig. 1A and Figs S3 and S4).