IFNG and allergic rhinitis: Rao and Han reported no change in IFN-γ in humans with allergic rhinitis; however, in another recent study, Zheng et al. did report a significant increase in IFN-γ together with a significant decrease in the Th2 cytokines IL-4 and GM-CSF (granulocyte-macrophage colony stimulating factor) [60, 62].