The congenic B6 mice, carrying the MT Tyk2 gene, presented high sensitivity to EMC-D virus-induced diabetes (Fig. 4a) associated with extensive β-cell damage (Fig. 4b), while congenic SJL/J mice with the WT Tyk2 gene showed resistance (Fig. 4c), thus providing evidence that the MT Tyk2 gene is responsible for determining susceptibility to EMC-D virus-induced diabetes. Here, TYK2 is linked to diabetes mellitus.