Since a considerable proportion of patients with PCOS has obesity (particularly abdominal), IR, glucose intolerance, type 2 diabetes mellitus (T2DM) and low-grade inflammation, i.e. disorders where lipocalin-2 secretion is affected, the present study was designed to assess a) serum lipocalin-2 levels in normal weight and overweight/obese patients with PCOS, and, b) the association between serum lipocalin-2 levels and anthropometric, metabolic, hormonal and ultrasonographic features of PCOS. This evidence concerns the gene LCN2 and obesity due to melanocortin 4 receptor deficiency.