In this regard, the aim of this study was to identify the relationship of the copy number of mtDNA in adipose tissues of different locations (SAT, mesentery (Mes), greater omentum (GO)), liver biopsy samples and MNCs with endothelial dysfunction markers (eNOS, endothelin-1 (ET-1), intercellular adhesion molecule 1 (iCAM-1), vascular cell adhesion molecule 1 (vCAM-1), vascular endothelial growth factor (VEGF)) and inflammatory mediators (TNF-α, IL-6, IL-8, C-reactive protein (CRP), leptin) in obese patients (body mass index (BMI) > 35 kg/m2) with and without type 2 diabetes. The gene discussed is IL6; the disease is type 2 diabetes mellitus.