Fibrinogen-like protein 2 (Fgl2), also known as fibroleukin, is secreted by T cells and is involved in diseases in which thrombosis plays a pivotal role,such as virus-induced fulminant hepatitis, fetal loss syndrome and xenograft rejection. Constitutively xpressed in cytotoxic T cells, Fgl2 exerts immunosuppressive effects on both T cell proliferation and dendritic cell maturation.
Fgl2 is a serine protease and directly cleaves prothrombin to thrombin. Fgl2 functions in the pathogenesis of diseases including viral-induced hepatitis and Th1 cytokine-induced fetal loss syndrome.