Mean fluorescence staining intensity of insulin was also reduced in donors with type 1 diabetes (0.082 ± 0.007 relative fluorescence units [RFU] vs 0.017 ± 0.002 RFU vs 0.020 ± 0.002 RFU for non-diabetic donors vs donors with short-duration type 1 diabetes vs donors with long-duration type 1 diabetes) (Fig. 3c). This evidence concerns the gene INS and type 1 diabetes mellitus.