Wei PZ, et al. - Given a crucial role of mitochondrial dysfunction in the pathogenesis and progression of diabetic nephropathy (DN), researchers explored the link between urinary and intra-renal mitochondrial deoxyribonucleic acid (mtDNA) levels and renal dysfunction in DN. Urinary sediment, urinary supernatant and intra-renal mtDNA levels were measured in patients with biopsy-proven DN and compared with baseline renal biopsy, kidney scarring and renal function decline in the subsequent 24 months. An easy detectability of mtDNA in urinary supernatant and kidney tissue, as well as the correlation of their levels with renal function and scarring in DN, was demonstrated.