IFNG and autoimmune disease: The association IFN-γ and autoimmune disorders is not surprising because IFN-γ is a potent proinflammatory cytokine which has a number of important roles including, increasing major histocompatibility gene complex (MHC) class I (MHC-I) and class II (MHC-II) antigen presentation, increasing the expression of toll-like receptors (TLR) by innate immune cells, promoting immunoglobulin G class switching, promoting the induction of chemokine secretion, macrophage activation and increased phagocytosis.