To characterize the potential mechanisms by which AQP1 enhances the migration and invasion of GBM cells in vitro, we evaluated the expression of cathepsin B and focal adhesion kinase (FAK), proteins that regulate cell migration and invasion, in the AQP1‐expressing U251 and U87 cells and control cells by western blot analysis.22, 23. Here, PTK2 is linked to glioblastoma.