The serum and vitreous TTR levels in DR patients were associated with DR progression [15]; TTR suppressed angiogenesis by affecting the angiopoietin-Tie signaling pathway in hyperglycemia [16], and enhanced the apoptosis of hRECs through a hypoxia-associated 78-kDa glucose-regulated protein (GRP78)-dependent pathway [17]. This evidence concerns the gene HSPA5 and Hyperglycemia.