Figure 1.

T‐cell immune checkpoint inhibitors and related ligands. TCR interaction with the antigenic peptide‐MHC complex displayed by professional APCs delivers the primary signal for T‐cell activation. The CD28 co‐receptor and other costimulatory receptors enhance the T‐cell stimulatory signal following interaction with their corresponding ligands. Immune checkpoint inhibitors including PD‐1, CTLA‐4, LAG3, TIGIT, TIM3, CD160, and 2B4 act to suppress T‐cell signal following interaction with their related ligands expressed on APCs