SLC1A2 and major depressive disorder: Since EAAT2 is a critical astrocytic glutamate transporter that maintains extracellular glutamate below excitotoxic levels, we speculate that the presence of the SLC1A2 rs4354668 C/C genotype (associated with a lower expression of EAAT2) may partially attenuate estrogen-mediated neuroprotection and lead to an increased susceptibility to MDD.