AQP4 and central nervous system cancer: Probably, the most striking aspect of glioma cells respect to normal astrocytes is the completely changed organization of AQP4 complexes: as mentioned above, in the normal brain AQP4 forms OAPs specifically localized to the astrocytic endfeet; in glioma cells typical endfeet are no more recognized, and AQP4 is not only up-regulated but also redistributed along the entire cell membrane [138] (Figure 2), with a parallel loss of the normal astrocyte-BCEC contacts at the BBB [139].