The absence of islet autoantibodies is not uncommon in long-duration diabetes, since 5-10% of people with type 1 diabetes do not have autoantibodies [5], but the absence of hallmark type 1 diabetes susceptibility HLA markers of DR3 and/or DR4 further makes the diagnosis of type 1 diabetes less likely in this case. This evidence concerns the gene TNFRSF25 and type 1 diabetes mellitus.