TYK2 and diabetes mellitus: In addition, if TYK2 promoter variant confer risk for the development of diabetes due to increased susceptibility to viral-infection, possible induction of autoimmunity against pancreatic β-cells triggered by viral infections, which is a well-documented hypothesis (Fairweather and Rose, 2002, Stene et al., 2010), was not a major pathogenic mechanism, in TYK2 promoter variant-associated susceptibility to type 1 diabetes.