PDGFB and Parkinson disease: We selected this model (line D PDGFb-SNCA) which overexpresses wild-type human SNCA from the PDGFb promoter, in part, based on the fact that increased expression of wild-type SNCA in humans can cause PD, as demonstrated in families with autosomal dominant PD due to duplication or triplication of the normal (wild-type) SNCA gene [21], [22], [47], [48].