Lysobisphosphatidic acid (also called BMP [bis(monoacylglycerol)phosphate]), a phospholipid in late endosomes/lysosomes, is increased in urine in G2019S-LRRK2 PD cases compared to healthy controls and is currently employed as a biomarker in clinical trials with LRRK2 kinase inhibitors30–32. Here, LRRK2 is linked to Parkinson disease.