Fig. 1From: Soluble immune checkpoints in cancer: production, function and biological significanceVarious ligand-receptor interactions between T cells and APCs (generalized to include all karyocytes). TIM-3, LAG3, PD-1, PD-L1, BTLA, and CTLA-4 are coinhibitory molecules present on the surface of T cells. OX40, TCR, CD28, and CD137 can transfer stimulatory signals into T cells, and CD40 can receive stimulatory signals from CD40L on T cellsBack to article page