The invention relates to the treatment and prevention of type I diabetes. More specifically, the invention relates to compounds that treat or prevent the body's immune system from destroying β-cells (i.e., insulin-producing cells in the pancreatic islets of Langerhans) by inhibition of JNK2, selective inhibition of JNK2, or inhibition of the expression of the MAPK9 gene or gene product. In one embodiment, the present invention contemplates the diagnosis, identification, production, and use of compounds which modulate MAPK9 gene expression or the activity of the MAPK9 gene product including but not limited to, JNK2, the nucleic acid encoding MAPK9 and homologues, analogues, and deletions thereof, as well as antisense, ribozyme, triple helix, antibody, and polypeptide molecules as well as small inorganic molecules. The present invention contemplates a variety of pharmaceutical formulations and routes of administration for such compounds.