IFNG and sarcoidosis: The hallmark finding of sarcoidosis are the presence of non-caseating epithelioid granulomas, which are believed to be an antigen-driven cell-mediated immune response involving CD4+ T cells that eventually differentiate into Type 1 T helper (Th1) cells which then secrete IL-2 and IFN-γ, supporting macrophage TNF-α production, promoting the cellular immune response [3, 4].