IFNG and systemic lupus erythematosus: During SLE pathogenesis, IFN-γ is secreted by Th1 and DN T cells; IL-17 is mainly produced by Th17 and DN T cells; meanwhile, IL-23 is indispensable for the later stabilization of Th17 cells and is able to induce the production of IL-17, IL-22, IL-6, and TNF-α in Th17 cells [43–45].