To investigate WT and mutated Kir2.1 channels intracellular distribution in astrocytoma cells, we carried out immunofluorescence experiments and observed that WT channels were mostly localized in cytoplasmic vesicles distributed in perinuclear areas (Fig. 3A, short arrows) and, in ∼20–30% of the cells, also at plasma membrane level (Fig. 3A, long arrows). Here, KCNJ2 is linked to astrocytoma (excluding glioblastoma).