INS and type 1 diabetes mellitus: Median relative fluorescence intensity of insulin and proinsulin were reduced in the triple-positive cells of donors with type 1 diabetes (of insulin, 12.55 vs 5.47 RFU for cells from non-diabetic donors vs donors with long-duration type 1 diabetes, respectively; of proinsulin, 8.69 vs 5.48 vs 2.05 RFU for non-diabetic donors vs donors with short-duration type 1 diabetes vs long-duration type 1 diabetes, respectively) (Fig. 4b, c), hinting at steady loss of beta cell insulin granules.