PSAP and neurodegenerative disease: An important role in the regulation of α-Syn levels is played by PSAP and its derivative Sap C. It has been shown that overexpression of PSAP reduces α-Syn levels and helps to slow down or prevent the onset of neurodegenerative diseases, thus exerting a neuroprotective effect, whereas knockdown of PSAP leads to an increase in α-Syn levels.