Despite the internalization and consequent functional downregulation of Kir4.1, there is still a significant fraction of this channel expressed in the membrane which, at the RMP of GBM cells, mediates a constitutive outward K+ current (Figure 1B) that might play a role in the redistribution of cell volume and the consequent change in cell morphology. Here, KCNJ10 is linked to glioblastoma.