To examine the functional significance of mTOR hyperactivation in GBA1/PD–DA neurons, we tested the effect of mTOR inhibition on α-synuclein aggregation, and the levels of phospho-α-synuclein/Ser129 (p-ASYN129), an α-synuclein species that is present in Lewy bodies (46). This evidence concerns the gene GBA1 and Parkinson disease.