Reactivity to one of the B chain peptides identified, preproinsulin33-47/B10-18, was shown to elicit a CD8+ T cell response in long-standing T1D patients who undergo islet graft rejection using an ELISpot for granzyme, interferon γ and IL-10 production and immunostaining with A2.1-peptide tetramers [58]. This evidence concerns the gene IL10 and type 1 diabetes mellitus.