TYK2 and autoimmune disease: Regarding genetic factors,tyrosine kinase 2 (TYK2) is a candidate genefor autoimmune diseases since it encodes a member of Janus Kinase (JAK) family oftyrosine kinases, which have a central role in immune response since they mediatesignaling pathways for several cytokines and type I interferon (IFN-I) (Ghoreschi et al., 2009; Strobl et al., 2011).