KCC2 is a member of the cation-chloride cotransporter gene family (1). It acts as a K-Cl cotransporter. KCCs normally lower intracellular chloride concentrations below the electrochemical equilibrium potential and depending on the chemical concentration gradients of potassium and chloride, KCC2 can operate as a net efflux or influx pathway. It is proposed to act as the main chloride extruder to promote fast hyperpolarizing postsynaptic inhibition in the brain (2, 3). KCC2 is expressed at high levels in neurons throughout the nervous system and immunofluorescence shows that the protein is localized at inhibitory synapses of the spinal cord (4). Studies in mice have shown that KCC2 reduces GABA's inhibitory signaling, resulting in motor defects, epilepsy, and anxiety-like behavior.