In Gaucher disease (GD), biallelic mutations in GBA underlie defective acid β-glucosidase (glucocerebrosidase, GCase) and buildup of the primary substrate, glucosylceramide (GluCer), and its inflammatory metabolite glucosylsphingosine (GlcSph) in the lysosomes (Grabowski et al., 2021). Here, GBA1 is linked to Gaucher disease.