The lowest sACE was associated with UCP3‐55C/UCP2‐866A/UCP2D (UCP3/2 CAD) haplotype in both studies, an SNP change from UCP3/2 CAD to CAI increasing sACE by 10·0 nmol his‐leu/ml/min in the T1DM. This evidence concerns the gene UCP3 and type 1 diabetes mellitus.