CD4 and Autoimmunity: Single‐antigen transgenic mouse models have been created to mimic autoimmunity by adoptive transferring diabetogenic cells, such as β cell specific CD4+ and CD8+ T cell clones from BDC2.5 and NOD8.3 mice, into NOD‐SCID mice.[16, 52, 53, 54] These models are simple because of their single‐antigen characteristic and are valuable for studying disease initiation.