Park1/Δ21-mutant flies were placed on 300 μM myriocin-enriched fly medium, and myriocin led to improved flying ability, increased ATP levels, and improved mitochondrial morphology (SI Appendix, Fig. S2 A–D), suggesting that ceramide is a shared player in PINK1- and Parkin-related PD. Here, PRKN is linked to Parkinson disease.