http://www.creativebiomart.net/description_3562_12.htm
Interferon-gamma (IFN-γ, also known as Type II interferon or immune interferon) is a 
cytokine produced primarily by T-lymphocytes and natural killer cells. The protein 
shares no significant homology with IFN-β or the various IFN-α family proteins. Mature
 IFN-γ exists as noncovalently-linked homodimers. Human IFN-γ is highly species 
specific and is biologically active only in human and primate cells. IFN-γ was originally 
characterized based on its antiviral activities. The protein also exerts antiproliferative, 
immunoregulatory and proinflammatory activities and is thus important in host defense 
mechanisms. IFN-γ induces the production of cytokines, upregulates the expression of 
class I and II MHC antigens, Fc receptor and leukocyte adhesion molecules. It modulates 
macrophage effector functions, influences isotype switching and potentiates the secretion 
of immunoglobulins by B cells. IFN-γ also augments TH1 cell expansion and may be required 
for TH1 cell differentiation.