This paradoxal effect of PD-1/PD-L1 blockade is reminiscent of the marked infiltration by highly proliferative Foxp-3Hi/CD45− CD4+ T cells (effector Tregs) reported in biopsies of gastric adenocarcinoma patients presenting with hyperprogressive disease under anti-PD-1 treatment which contrasted with responders who displayed a decline in intratumoral Tregs frequencies upon treatment [103]. This evidence concerns the gene PDCD1 and gastric adenocarcinoma.