Clonogenic assays, scoring for the ability of cells to form colonies, confirmed selective PARPi hypersensitivity in RB1-defective osteosarcoma for all three PARPi (Fig. 2a–j, raw data Supplementary Fig. 2a–c) with half maximal inhibitory concentrations (IC50) for RB1-defective osteosarcoma matching or below that determined for BRCA2-mutant CAPAN1, and differentials in median IC50 value comparing RB1-normal and RB1-defective groups of 14-fold (olaparib), fivefold (niraparib) and eightfold (talazoparib) (Fig. 2c, f, i and Supplementary Table 1). The gene discussed is BRCA2; the disease is osteosarcoma.