The irradiated Tyk2 KO recipient mice that were transferred spleen cells derived from either WT donor mice or Tyk2 KO mice developed diabetes 7 days after EMC-D virus infection, whereas the irradiated WT recipient mice received spleen cells derived from either WT donor mice or Tyk2 KO mice did not develop diabetes (Fig. 2d). This evidence concerns the gene TYK2 and diabetes mellitus.