The key markers of the Aldh1a1+/Sox6+ ventral-tier SNc population, which is particularly vulnerable in models of Parkinson’s disease (PD) (Cai et al., 2014; Liu et al., 2014; Poulin et al., 2014), were enriched in our SNr RiboTag IPs (Aldh1a1, Sox6, Aldh1a7, and Anxa1). Here, SOX6 is linked to Parkinson disease.