Two lines of Eαd-expressing NOD mice were established by continuously backcrosslng [Eαd B6 transgenic mice × NOD] F1 to parental NOD or directly microinjecting the Eαd gene into fertilized NOD eggs. Similarly, Aβk-expressing transgenic NOD mice were produced. Subsequent histological examination of pancreatic tissues revealed that autoimmune insulitls was prevented in Eαd backcross and transgenic mice but not in Aβk transgenic mice.