Adverse stress signals stimulate nerve endings to excessively release glutamate, which not only produces excitotoxicity but also causes elevated extracellular ATP levels in the brain, leading to a cascade response that promotes activation of microglia P2X7 receptors and elevated IL‐1β levels, inducing inflammation in the CNS and ultimately leading to depression.51 The gene discussed is P2RX7; the disease is major depressive disorder.