COX4I1 and Parkinson disease: Consistent with previous findings, dopaminergic neurodegeneration in α‐Syn transgenic mice primarily affects a dorsomedial ALDH1A1‐positive subpopulation, which is also more susceptible to cytotoxic α‐Syn aggregation.[5a] In PD patient SN tissues, we observed more extreme Sox6 and ALDH1A1 cleavage by AEP, accompanied by complete eradication of Satb1 and COX IV.