The first insight into the structure of microtubule-associated LRRK2 came from a reconstruction, using correlative light-electron microscopy (CLEM) and cryo-electron tomography (cryo-ET), of a double-helical filament of LRRK2 wrapped around microtubules from cells overexpressing a GFP-labeled version of the full-length protein containing the PD-linked mutation I2020T (46). The gene discussed is LRRK2; the disease is Parkinson disease.