HMGB1 and endothelial dysfunction: To test this hypothesis, we measured the levels of BDNF, HMGB1, soluble RAGE (sRAGE), biomarkers of inflammation and endothelial dysfunction including MCP-1, and sICAM-1 and the oxidative stress and lipid peroxidation marker thiobarbituric acid reactive substances (TBARS) in the vitreous fluid and serum from a series of patients with PDR.