Parving et al. [44], in their observational followup study of type 1 diabetic patients with diabetic nephropathy receiving ACE inhibitor captopril (n = 35 and n = 169), have reported that the DD genotype reduces the long-term beneficial effect of ACE inhibition on the progression of diabetic nephropathy in patients with IDDM. This evidence concerns the gene ACE and type 1 diabetes mellitus.