gBK channels (a) facilitate an increased outwardly K⁺ current. Ca²⁺ input for gBK channels is provided by IP₃R (b). ClC-3 channels facilitate an increased Cl⁻ outwardly current. (a) and (c) facilitate increased H₂O movement through osmosis (d) over the plasma membrane. Glioblastoma AMPA receptors (e) lack the GluR2 subunit and therefore have increased Ca²⁺ permeability. Amiloride-sensitive BNaC channels (f) are expressed in glioblastoma. K_ir channels are mislocalized to the cell nucleus (g), diminishing inwardly rectifying K⁺ currents.