a, Response of ALL patient-derived xenografts treated ex vivo with different chemotherapeutic drugs in combination with the GSK2830371 PPM1D inhibitor. b, Response of ALL patient-derived xenografts treated ex vivo with daunorubicin (DNR) as a single-agent or in combination with the ZW1231 TDP2 inhibitor. c, Western analysis of DNA damage and response markers in REH cells treated with the VE821 ATR inhibitor and maphosphamide. d, Cell viability of REH cells treated with VE821 and maphosphamide alone and in combination. e, Response of ALL patient-derived xenografts treated ex vivo with VE821 and maphosphamide as single agents and in combination. Bars in a, b and e and curves in d indicate relative cell viability compared with vehicle treated controls.