Until now, the role of AQP4 in PTBE of meningiomas is not clear given that in vasogenic edema, water entry in the brain is AQP4-independent contrary to cytotoxic brain edema which is AQP4-dependent (Papadopoulos et al. 2004b; Papadopoulos and Verkman 2007; Zador et al. 2009). This evidence concerns the gene AQP4 and meningioma.