Such approaches have relied on the targeting of immune checkpoints, such as PD‐1, to alleviate inhibitory constraints on T‐cell‐mediated anti‐tumour immunity in immunogenic tumours, or alternatively on adoptive T‐cell therapy, especially that employing CAR T cells (Pardoll, 2012; Yong et al, 2017; Ribas & Wolchok, 2018). This evidence concerns the gene PDCD1 and neoplasm.