HLA-A and type 1 diabetes mellitus: Conversely, HLA-A/B/C/E, HLA-A and HLA-B expression in α-cells from T1D islets devoid of β-cells (INS-deficient islets, IDIs; Supplementary Fig. 8d) was lower than in α-cells from T1D ICIs and comparable to that of ND ICIs (Fig. 7d).