BMPs are important for endosomal and lysosomal function, and altered levels of BMP species have been reported in a group of diseases, known as lysosomal storage disorders, in which lysosomal dysfunction leads to the accumulation of secondary metabolites, as observed in Gaucher disease, Fabry disease, mucopolysaccharidosis, Pompe disease, and drug-induced phospholipidosis [20], [21]. Here, CLN5 is linked to lysosomal storage disease.