Furthermore, in a human induced pluripotent model of tauopathies, introducing common FTDP-17 mutations (FTD with parkinsonism linked with chromosome 17) reduced KCC2 expression in differentiated neurons (García-León et al., 2018), further suggesting that reduced KCC2 is a driver of neurodegenerative disease pathology, particularly in tauopathies, such as AD and FTD. This evidence concerns the gene SLC12A5 and Parkinson disease.