We treated LRRK2 R1441G cells with DNL151, a selective LRRK2 kinase inhibitor currently being assessed in late-stage clinical studies for the treatment of PD (Supplementary Fig. S3B), for 72 h and demonstrated DNL151 treatment fully normalized the levels of GlcCer(d18:1/24:1), the most significantly elevated GlcCer species observed in LRRK2 R1441G cells compared to WT cells (Fig. 3C). Here, LRRK2 is linked to Parkinson disease.