PDCD1 and neoplasm: We observed that higher doses of olaparib (50 mg/kg) and AZD1775 (50 mg/kg) significantly increased PD-L1 expression on AT3 tumours (Fig. 2b) which corresponded with a limited but significant improvement in anti-tumour efficacy of olaparib, AZD1775 and anti-PD-1 (Supplementary Fig. 4d) compared with the two-drug combination of olaparib and AZD1775.