{"type":"root","children":[{"type":"paragraph","children":[{"type":"text","value":"Inducible T-cell Costimulator (ICOS) is also known as CD278. CD278 is homologous to the CD28/CTLA-4 proteins and is expressed on activated CD4+ and CD8+ T cells and unstimulated thymocytes. CD278 plays a major role in regulation of cell-cell signaling, adaptive immune response, and cell proliferation. Interaction of CD278 and its ligand ICOS-L results in increased production of interleukins, which promote differentiation of T follicular helper cells (Tfh) and regulatory T cells (Tregs). CD278/ICOS-L interaction has been shown to promote either antitumor T cell response or pro-tumor responses when triggered in Tregs. Therefore, both agonistic and antagonistic monoclonal antibodies targeting this pathway can be potential cancer immunotherapy."}]}]}