PD-L1-positive cells determined by confocal immunofluorescence (up to 20%) varied considerably (Supplementary Fig. 5C–F), However, 60% of organoids obtained from the biopsy of a PD-L1-positive patient were negative for PD-L1 (Supplementary Fig. 5D), consistent with the immunohistochemical observation that only some tumour cells express PD-L1. The gene discussed is CD274; the disease is neoplasm.