Of course VEGF and IL-6 were not only responsible factors of diabetic retinopathy, therefore, other reported intravitreous cytokines/chemokines including ICAM (10), SDF-1 (28), or polyamines including spermidine, putrescine, and spermine (29), should be studied in future. This evidence concerns the gene CXCL12 and diabetic retinopathy.