SLC1A2 and neoplasm: Moreover, the high glutamate levels in tumor tissue are also a consequence of both increased release of a glutamate agonist in the synaptic cleft, induced by mutation of IDH 1/2 (isocitrate dehydrogenase 1 and 2) (9), and a reduced glutamate removal from extracellular space, caused by the downregulation of excitatory aminoacidic transporter EAAT2 (35).