Figure 2. A comparison of plasma concentrations of PDGF-BB, TIMP-1, TIMP-2, ANG-1, CXCL16, and VEGFR2 in the validation cohort. ANG-1, PDGF-BB, TIMP-2, and VEGFR2 were significantly higher in non-proliferative diabetic retinopathy patients than in diabetes mellitus patients. However, there were no significant difference of CXCL16 and TIMP-1.