However, chronically increased leptin produced by AT in obesity interferes with the IFN signal transduction through increasing suppressor of cytokine signaling 3, which negatively regulates the Janus Kinase-STAT pathway, causing the limited IFN in vivo to fail in inducing antiviral ISGs transcription 80, 82. The gene discussed is IFNA1; the disease is obesity due to melanocortin 4 receptor deficiency.