MMP9 and hemorrhagic stroke: The protective M2-like microglia and monocytes/macrophages exert their effect through the secretion of remodeling factors, such as VEGF, BDNF, and matrix metalloproteinase-9 (MMP-9) [23,24,25], in addition to protective cytokines, such as transforming growth factor-β (TGF-β) and IL-10 [26,27], which may facilitate anti-inflammation, axonal outgrowth, and angiogenesis after ischemic [20,21,27,28] and hemorrhagic stroke [22,29,30].