AQP4 and neoplasm: Several in vitro and in vivo studies have reported reduced invasive capacity and migration in tumors after AQP4 depletion or downregulation (Ding et al., 2010, 2011; Cheng et al., 2017) by decreasing water permeability, which in turn upregulates transmembrane water fluxes during tumor or healthy astroglial cell movement (Huang et al., 2021).