Immune checkpoint receptors expressed on immune cells and their respective ligands on antigen-presenting cells (APCs) and/or tumor cells highlighting select targetable receptors. (PD-1) Programmed cell death protein 1, (PD-L1) programmed cell death-ligand 1, (CTLA4) cytotoxic T-lymphocyte-associated protein 4, (LAG3) lymphocyte activation gene 3, (MHC-II) major histocompatibility complex-class II, (TIM3) T-cell immunoglobulin and mucin-domain containing 3.