More interestingly, growth factors (GFs) and neurotrophic factors (NFs) including platelet-derived growth factor (PDGF) and BDNF are proposed as main ingredients for the paracrine effects of hypoxia-cultivated stem cells [15,16,17] and are known to promote nerve survival and control synapses in glaucoma eyes [18]. This evidence concerns the gene BDNF and glaucoma.