KCNN4 and glioblastoma: In fact, due to the cytosolic calcium fluctuations during GBM cells migration, members of the family of Ca2+-activated K+ channels such as KCa3.1 (intermediate conductance K+ channel) and the BK channel (large conductance K+ channel), are overexpressed in 32% of glioma patients, and there is a linear correlation between the expression of these channels and the progression of the pathology.