SOX6 and Parkinson disease: The proteins identified thus far are not exclusively expressed in SNpc or VTA DA neurons but are generally enriched in only one group.[28] Sox6 and ALDH1A1 have been identified as target proteins for the susceptibility of dopaminergic neurons in PD,[8, 29] however, the mechanisms of how Sox6 and ALDH1A1 mediate the onset of PD remain unclear.