LRRK2 and Parkinson disease: In peripheral cells from LRRK2-PD patients as compared to healthy controls, quantitative mass spectrometry-based assays can detect increased phospho-Rab10 levels (Karayel et al., 2020), and centrosomal cohesion deficits serve as a sensitive cellular biomarker for enhanced LRRK2 kinase activity (Fernandez et al., 2019).