INS and type 1 diabetes mellitus: In comparison with previous findings demonstrating elevated proinsulin/insulin ratio in plasma of adults with established type 1 diabetes [32] and increased proinsulin/insulin area ratio in whole-slide pancreas sections from donors with recently-diagnosed type 1 diabetes [33], we found that the proinsulin/total insulin intensity ratio is not increased and that proinsulin-positive cells and insulin-positive cells are both significantly reduced in islets from donors with type 1 diabetes.