A common polymorphism in the promoter for the glutamate transporter EAAT2/GLT1, which is expressed in white matter (Domercq and Matute, 1999; Domercq et al., 1999), leads to less transporter expression, a raised extracellular glutamate concentration and worse outcome in stroke (Mallolas et al., 2006). The gene discussed is SLC1A2; the disease is stroke disorder.