Fig. 1From: Costimulatory and coinhibitory immune checkpoint receptors in head and neck cancer: unleashing immune responses through therapeutic combinationsThe Immune Synapse. The balance between costimulatory (green) and coinhibitory signals (red) alters the net stimulating effect of TCR signaling mediated through antigen presentation on MHC (blue). Adapted from Ferris RL, J Clin Oncol. 2015;33(29):3293–304Back to article page