At the histological and molecular level, these rats display many features observed in human T1DM, such as overexpression of interferon-α and MHC class I molecules, a progressive infiltration of various immune cells into the islets 61, a decrease in CD4+ T cells, and a loss of CD8+ T cells 62, which collectively make autoimmune reactions to β-cells more likely to occur. Here, CD4 is linked to type 1 diabetes mellitus.