INS and type 1 diabetes mellitus: The mean cytoplasmic area of beta cells positive for insulin was reduced in islets from donors with short- or long-duration type 1 diabetes (86.83 ± 1.96 μm2 vs 73.52 ± 4.86 μm2 vs 49.75 ± 5.08 μm2 for non-diabetic donors vs donors with short-duration type 1 diabetes vs long-duration type 1 diabetes, respectively) (Fig. 2c).