MMP9 and meningioma: Evidence from the literature suggests that MR imaging of cellularity and invasiveness, angiogenesis, capillary permeability, and microvasculature in meningioma can be corroborated using molecular markers such as Hypoxia-inducible factor-1α, matrix metalloproteinase-9, and vascular endothelial growth factor (Eberlin et al., 2013; Iwado et al., 2012; Jensen, Soleau, Bhayani, & Christiansen, 2002; Kaynars et al., 2008; Toh et al., 2014).