The results of the present meta-analysis showed that SLE patients had significantly lower percentage of Th1 cells, a higher percentage of Th2 cells and higher levels of Th1- and Th2-associated cytokines (IFN-γ, TNF-α, IL-2, IL-10, IL-6 and IL-4) than HCs. The gene discussed is IFNG; the disease is systemic lupus erythematosus.