TYK2 and diabetes mellitus: It should be noted that the Tyk2-deficient mice infected with EMC-D virus produced a high level of IFN but failed to rescue the mice from developing diabetes because high level of IFN could reverse the antiviral response in fibroblasts24, but not pancreatic β-cells as shown by this study, suggesting the β-cell-specific unresponsiveness to a high level of IFN is critical in losing the capability to evade from virus-infected cell damage.