CD8A and type 1 diabetes mellitus: While both T and B lymphocytes are reported in insulitis lesions, cytotoxic CD8 T-cells appear to be the predominant population and could target beta cells expressing elevated levels of Human Leucocyte Antigen (HLA) class I molecules [18]; moreover, over-expression of class I (and class II) molecules may be associated with viral infections, suggesting a key role in T1D pathogenesis [19].