RMDN3 and Parkinson disease: Disruption of the VAPB‐PTPIP51 tethers by Parkinson's disease‐linked α‐synuclein involves its direct binding to VAPB, and GSK3β is a known negative regulator of the VAPB‐PTPIP51 interaction (Paillusson et al., 2017; Stoica et al., 2014, 2016).