Firstly, CD8+ T cells are the dominant cell type found in insulitic lesions in the pancreas of patients with type 1 diabetes 3, 4, 5, and hyperexpression of human leucocyte antigen (HLA) class I molecules in this lesion has the potential to enhance peptide presentation to infiltrating CD8+ T cells 3, 4, 5, 6, 7, 8. The gene discussed is CD8A; the disease is type 1 diabetes mellitus.