One such LSD is Gaucher disease (GD), caused by mutations in the GBA1 gene, which encodes the lysosomal enzyme, acid-β-glucosidase (glucocerebrosidase, GCase) [15], resulting in the accumulation of the sphingolipid glucosylceramide (GlcCer) and its deacylated form, glucosylsphingosine (GlcSph) [16, 17]. Here, GBA1 is linked to Gaucher disease.