AQP4 and glioma: In particular, serum-starved cultures of the highly aggressive human glioma cell line U87 either in control conditions (WT) or selectively transfected with the M23-AQP4 isoform (forming AQP4-OAPs and henceforth called AQP4-OAPs) or with the M1-AQP4 isoform (forming AQP4-tetramers and henceforth called AQP4-tetramers) were analysed.