LRRK2 and Parkinson disease: In Parkinson’s disease, the neuronal loss caused by leucine-rich repeat kinase 2 (LRRK2) G2019S can be reduced by feeding ursodeoxycholic acid (UDCA) via a mechanism involving the restoration of adenosine 5′-triphosphate levels back to normal levels, indicating that this bile acid may be a therapeutic agent for Parkinson’s disease24.