To address this, single-cell profiling studies have identified a ventrally biased Sox6+/Aldehyde Dehydrogenase 1A1 (Aldh1a1+) dopamine neuron subcluster in humans and mice.7–9 The location of the cell bodies (ventral SNc) and axonal projections (dorsal striatum) of Aldh1a1+ cells corresponds to the patterns of neuron and projection loss observed in PD.10–12 Additionally, recent research identified Annexin 1 (Anxa1) as a subset of Aldh1a1+ dopamine neurons occupying the ventral-most SNc. Here, SOX6 is linked to Parkinson disease.