TYK2 and infection: The rate of transcription for IFN, AR1, JAK1, and TYK2, transducers of IFN synthesis activating signal (ISG), is higher in patients with mild or moderate infection associated with the increased plasma level of IFN, by contrast with a decrease in ISG expression mediated by inhibitor genes MX1, IFITM1, IFIT2 and decreased IFN I blood level in patients with severe infection (151, 152).