An established T1D endotype is associated to early life disease onset in patients that are diagnosed < 7-years of age that is characterized by aggressive insulitis with abundant CD8+ T and CD20+ B cell infiltration (12, 13), The percentage of patients with onset-age of diagnosis in our cohort under 7-years was only slightly higher in T1D-group-A (12%) than in T1D-group-B (10%) and thus seems not to explain the immune phenotypic subgroups as we present here. Here, CD8A is linked to type 1 diabetes mellitus.