GJA1 and glioblastoma: Connexin 43(Cx43) participates in these mechanisms as well, but we have shown that Cx30 is rather an on-off expression in gliomas,28 whereas Cx43 can often be present and not functional in gliomas.29 GAT-3, the membrane transporter for the inhibitory amino acid GABA is overexpressed by glioblastoma cells30 and can alter the synaptic of this neurotransmitter, in a fashion similar to that of EAAT1 and 2 for the excitatory neurotransmitter glutamate.