CD274 and neoplasm: The expression of PD-L1 on tumour cells and PD-1 on immune cells have both been investigated as predictive biomarkers for anti-PD-1 therapies in clinical trials (Garon et al., 2015; Carbone et al., 2017; Schmid et al., 2020) and are currently used as biomarkers in NSCLC and urothelial cancers.