[86] observed that in highly glycolytic malignant tumors, Treg cells rapidly absorb lactate from the TME via MCT1, stimulating the nuclear factor of activated T cells 1 (NFAT1) to enter the nucleus and increase PD‐1 expression, while PD‐1 expression in effector T cells is suppressed, leading to therapeutic failure [215]. Here, PDCD1 is linked to cancer.