SYT1 and Parkinson disease: Taken together, these data show the reduction of the key calcium regulatory proteins PLD1, iPLA2 and synaptotagmin-1 in GBA-N370S iPSC-dopamine neurons suggest a possible link between mitochondrial calcium dysregulation, reduced mitochondrial function, and impaired neurophysiological activity which may ultimately contribute to the preferential vulnerability of dopamine neurons in PD.