IFN-γ is a key component of the immune response to viral infections. It is produced by NK, NKT, and γ/δ T cells during early stages of infection and by CD4 and CD8 T cells later during the adaptive immune response. During infection, the role of IFN-γ includes protection, clearance, and modulation of the immune response. IFN-γ modulates epithelial cell functions and may play a role in intestinal wound healing as it might help preserve the integrity of the intestinal epithelium. It has been published that IFN-γ enhances IL-27 secretion, and the treatment of rats in a model of arthritis, IFN-γ/IL-27 successfully controlled arthritic inflammation and inhibited mediators of inflammation, angiogenesis, cell survival, apoptosis, and tissue damage. Nevertheless, IFN-γ has been associated with multiple inflammatory and autoimmune diseases such as arthritis, lupus nephritis, diabetic retinopathy, lung fibrosis, allergic conjunctivitis, and pediatric SLE. Rat IFN-γ protein has 39%?homology with humans and 85% homology with mice proteins. Due to the high homology between rat and mouse IFN-γ, there is a strong affinity for rat IFN-γ on mouse cells.