title: Reply to: Gray et al.
authors.affiliation: Morton and Gloria Shulman Movement Disorders Centre and the Edmund J. Safra Program in Parkinson's disease, Toronto Western Hospital, Toronto, Ontario, Canada.
authors.forename: Naomi P
authors.initials: NP
authors.lastname: Visanji
authors.forename: Connie
authors.initials: C
authors.lastname: Marras
authors.forename: Louis W C
authors.initials: LW
authors.lastname: Liu
authors.forename: Lili-Naz
authors.initials: LN
authors.lastname: Hazrati
authors.forename: Anthony E
authors.initials: AE
authors.lastname: Lang
mesh_terms: D003106:Colon / Q000378:metabolism*; D017615:Enteric Nervous System / Q000378:metabolism*; D006801:Humans; D010300:Parkinson Disease / Q000175:diagnosis*; D051844:alpha-Synuclein / Q000378:metabolism*
chemical_list: D051844:alpha-Synuclein