Thus, we searched online both of these databases for the expression changes of Foxa1, Foxa2, Aldh1a1, Nr4a2, Aadc, Th, En1, and Slc6a3. The levels of these mRNAs were down-regulated in several studies comparing expression profiles of the SNpc samples from PD patients and age-matched healthy subjects (Hauser et al., 2005; Zhang et al., 2005; Moran et al., 2006; Lesnick et al., 2007), indicating that not only Foxa1/2 factors, but also several Foxa1/2-regulated genes are affected in PD patients. Here, TH is linked to Parkinson disease.