FrontiersAgingNeuroscience“Aiming for Study Comparability in Parkinson’s Disease: Proposal for a Modular Set of Biomarker Assessments to be Used in Longitudinal Studies” has been published in Frontiers in Aging Neuroscience. This research was supported by JPND through the BioLoC-PD working group, selected under the  2014 call for working groups to inform cohort studies in neurodegenerative disease research.