The tyrosine kinase 2 (Tyk2) gene encodes a signal-transducing molecule associated with IFN receptor, IL-12 receptor, and IL-23 receptor, mediating interferon response, both Th1- and Th17-type immune reactions, and playing a major role in resistance to various infections including viruses, bacteria, and parasites [12,13]. This evidence concerns the gene TYK2 and infection.