Shen Y, et al. - In this cross-sectional study, researchers discovered vitreous and serum levels of high mobility group box-1 (HMGB-1) in patients with proliferative diabetic retinopathy (PDR) and illustrated their association with receptor for advanced glycation end products (RAGE), vascular endothelial growth factor (VEGF) and interleukin-1β (IL-1β). Participants with PDR who had vitrectomy were registered and the control group involved non-diabetic eyes. ELISA analyzed vitreous and serum samples for HMGB-1, RAGE, VEGF and IL-1β. A positive correlation was observed between serum and vitreous levels of HMGB-1 in PDR patient, whereas a negative correlation was recorded between serum and vitreous levels of VEGF in PDR patient. The result indicates the existence in PDR of a pro-inflammatory and angiogenesis state as demonstrated by higher concentrations of HMGB-1, RAGE, VEGF and IL-1β in both the vitreous and serum. HMGB-1 could contribute to the cross-talk relationships between angiogenesis and inflammation and could be a novel therapeutic objective for inhibiting PDR progression.