This assumption is consistent with recent findings about an inhibitory effect of anthocyanin delphinidin-3-O-glucoside and its metabolite delphinidin on the negative regulators, immune checkpoints PD-1 and PD-L1, resulting in the activation of an immune response in the tumor microenvironment and the induction of cancer cell death [52]. The gene discussed is PDCD1; the disease is neoplasm.