Hadjadj et al. have reported about the elevated APN concentrations observed in patients with DR and neuropathy and Ouchi et al. have reported that APN acts as an anti-inflammatory plasma protein and modulates the vascular remodeling linked to obesity [4, 23, 24, 26]; therefore, we hypothesized that systemic and local APN levels, reflecting microvascular inflammation, could be a marker of DR and its progression and compared these concentrations to the level of VEGF and other cytokines known to be related to DR development and progression. The gene discussed is ANPEP; the disease is obesity due to melanocortin 4 receptor deficiency.