PDCD1 and neoplasm: Here, we showed that the expressions of PD-1, Tim-3 and TIGIT on Vγ9Vδ2+ T cells and CD8+ T cells are regulated by the 1α,25(OH)2D3/VDR signaling pathway, which contributes to T-cell cytotoxicity under the condition of tumor-antigen and T-cell receptor (TCR) activation.