We investigated in our study with 13patients with type 1 diabetes mellitus and 13 healthy control glucoseutilisation after administration of C-peptide (8 pgmol/kg/body weight/min)over 2 hours during an euglycemic clamp procedure with either ahigh-dose (1.0 Ul/kg body weight/min) or a low-dose insulin infusion (0.25 mU/kg body weight/min).The C-peptide levels reached are shown in Figure 1. This evidence concerns the gene INS and type 1 diabetes mellitus.