Description
Inducible co-stimulator (ICOS) is an inducible homodimeric costimulator protein that is structurally and functionally related to CD28. It is a third member of the CD28/CTLA4 family and it is expressed on activated T cells. ICOS regulates CD28-dependent and CD28-independent CD4 (+) subset (Th1 and Th2) responses. ICOS is a major regulator of the adaptive immune system and therefore, has a protective role in inflammatory autoimmune diseases