Patients with proliferative and non-proliferative diabetic retinopathy are characterized by the abundance of S100A family proteins (S100A4, A100A6, S100A8, S100A11), but the most promising protein is S100A13 [31], which is the only S100A protein that has not been observed in our study as mentioned above (Supplementary Materials and Table 1). This evidence concerns the gene S100A13 and proliferative diabetic retinopathy.