GLT-1 (also known as EAAT2) is responsible for 80%–90% of all extracellular glutamate reuptake activity (Lin et al., 2012; Takahashi et al., 2015), but both GBM tumor tissue and cell lines show an almost complete absence of the transporter (Ye et al., 1999; de Groot et al., 2005). The gene discussed is SLC1A2; the disease is glioblastoma.