SNCA and Parkinson disease: The H4 neuroglioma cell line was chosen because it has been previously used to interrogate BAG5 function and PD-relevant molecular pathways, including alpha-synuclein aggregation (McLean et al., 2002, 2004; Klucken et al., 2006, 2012; Kalia et al., 2011; Danzer et al., 2012).