TH and Parkinson disease: Furthermore, evidence of αSyn-mediated inhibition of tyrosine hydroxylase (TH) and upregulation of dopamine transporters strengthens the case for the importance of αSyn in PD (as reviewed by; Dev et al., 2003; Uversky, 2007; Breydo et al., 2012; Lashuel et al., 2012; Deleersnijder et al., 2013).