The increased NKCC1 activity, which drives neuronal chloride influx causing the depolarizing effect of GABA, may not be counter-balanced by KCC2 due to its lower expression in glioma tissues (Conti et al., 2011; Pallud et al., 2014; Huberfeld and Vecht, 2016). The gene discussed is SLC12A5; the disease is glioma.