Members of the plasmalemmal cation-chloride cotransporter (CCC) family, such as the neuron-specific K+/Cl− extruder, KCC2, and the ubiquitously expressed Na+-K+-2Cl− cotransporter, NKCC1 (coded by the Slc12a2 gene), have received a steeply increasing amount of attention in research on central nervous system (CNS) diseases, ranging from neuropsychiatric diseases to epilepsy, stroke, and dementia [1–6]. This evidence concerns the gene SLC12A2 and dementia.