Dysregulated DA metabolism has been linked to SNpc vulnerability in PD since post mortem analyses showed decreased ALDH1A1 mRNA in PD SNpc but not VTA (Liu et al., 2014) and higher DOPAL:DOPAC and DOPAL:DA ratios in PD putamen (Goldstein et al., 2011, 2013). The gene discussed is ALDH1A1; the disease is Parkinson disease.