In CRC, Tregs heighten their suppressive function by elevating surface molecules such as CD39, CTLA-4, and PD-1 (57, 58), and by secreting IL-10 and IL-35, which jointly modulate the B-lymphocyte-induced maturation protein 1 (BLIMP1) inhibitory axis in CD4+ and CD8+ TILs (59). Here, PDCD1 is linked to colorectal carcinoma.