In fact, the release of chemokines involved in the recruitment of macrophages—such as TNF-α (highly detected in NPDR patients; Boss et al., 2017), CINC-3, CXC3CL1, LIX, and MIP-3α is potentiated, while the levels of neuroprotective factors—such as ciliary neurotrophic factor (CNTF), beta nerve growth factor (β-NGF) or tissue inhibitor of metalloproteinase 1 (TIMP-1)—are unchanged. This evidence concerns the gene CCL20 and non-proliferative diabetic retinopathy.