The local proliferative capacities of GP-specific (β cell specific) T cell receptor (TCR) transgenic CD4+ (Smarta; Fig. 1, K and L) and CD8+ (P14; Fig. 1, M and N) T cells were investigated by adoptive transfer of CellTrace Violet–labeled cells to mice undergoing diabetes induction treated with 6-OHDA or vehicle control on day 7 after infection. This evidence concerns the gene CD4 and diabetes mellitus.