Interferon gamma, IFNgamma, is a major immune-modulating molecule produced mainly by T cells and natural killer cells activated by antigens, mitogens or alloantigens. Most immune cells express IFN gamma receptors and respond to IFN gamma -induced signaling by up-regulating MHC class I expression. IFN gamma does not show cross-reactivity with. Recombinant IFN gamma is a non-glycosylated Protein, containing 134 amino acids, with a molecular weight of 15.6 kDa.