Naïve CD4+ T cells differentiate into Th1 cells with the expression of key transcription factors T‐box transcription factor 21 (T‐bet) and signal transducer and activator of transcription (STAT) family proteins, which are mediated by IL‐12 and IFN‐γ in response to intracellular pathogenic infections, inflammatory, and autoimmune diseases, such as asthma, inflammatory intestinal disorders, and lupus.16, 17, 18, 19. The gene discussed is IFNG; the disease is infection.