This study evaluated 3-hydroxyacyl-CoA-dehydrogenase and citrate synthase activities, uncoupling protein content, oxidative stress (measured by 4-hydroxy-2-nonenal), fiber type distribution, and mitochondrial respiration in muscle biopsies obtained from T2DM patients and non-diabetic male subjects. The gene discussed is EHHADH; the disease is type 2 diabetes mellitus.