Fig. 2
From: Novel immune checkpoint targets: moving beyond PD-1 and CTLA-4
Current and emerging immune checkpoint receptors and their respective ligands. Various immune checkpoint molecules expressed on T cells were shown with their ligands. Immune checkpoints such as PD-1, CTLA-4, LAG-3, TIM-3, TIGIT bound with their respective ligands on APCs and/or tumor cells, triggering a negative or positive signal to T cells response