Quantitative deficiencies of CD4+ iNKT cells has been observed in type 1 diabetes patients,43 and while transfer of CD4− iNKT cells exacerbated the incidence of diabetes in transgenic NOD mouse models, the CD4+ iNKT cells prevented diabetes development,44 demonstrating its importance in regulating the risk of developing type 1 diabetes. The gene discussed is CD4; the disease is diabetes mellitus.