For proliferative diabetic retinopathy, VEGF levels were measured in the range of 500 pg/ml to 1 ng/ml and the minimal levels of neutralizing ranibizumab were evaluated at 10 μg/ml (the levels found at four weeks after injection), not necessarily correlating well with VEGF levels [37-39]. Here, VEGFA is linked to proliferative diabetic retinopathy.