However, the relationship between ALDH1A1 expression and broader dopaminergic pathway gene co-expression has not been systematically characterized across multiple independent datasets.<h4>Methods</h4>Gene expression correlations were analyzed across seven independent human SN microarray datasets (<i>n</i> = 156; 70 controls, 86 PD) from the Gene Expression Omnibus. The gene discussed is ALDH1A1; the disease is Parkinson disease.