Figure 1.

Mechanism of anti-PD1 and anti-PDL1 checkpoint blockades.

Notes: PD1 is expressed by T cells. PDL1 is expressed in tumor cells and tumor-infiltrating immune cells. Combination of PD1 and PDL1/PDL2 contributes to the suppression of T-cell function. Inhibiting the interaction of PD1 and its ligands can significantly enhance T-cell function, resulting in antitumor activity. Reprinted from Cancer Treat Rev, 41(10), Meng X, Huang Z, Teng F, Xing L, Yu J, Predictive biomarkers in PD-1/PD-L1 checkpoint blockade immunotherapy, 868–876, Copyright (2015), with permission from Elsevier.⁹⁴