BDNF and ischemic stroke: Another key factor involved in the pathophysiology of ischemic stroke is hypoxia, which is the master regulator of intracellular oxygen sensing and adaptation and can induce the synthesis of pro-growth and vessel-stabilizing factors such as Ang2 (angiopoietin 2), SEMA3G (semaphorin 3G), and BDNF (brain derived neurotrophic factor) [[25], [26], [27]].