T1D progress depends both on the genetic backgroundand on environmental conditions.2 CD4 T-cellsplay a central role in the initiation and progression of the disease,as exemplified by the observation that major histocompatibility complex(MHC) II cluster variants are the most associated risk factors withT1D3 and other disease risks related tothe function of CD4. This evidence concerns the gene CD4 and type 1 diabetes mellitus.