Background：The LASS （longevity assurance homolog） family members are highly conserved from yeasts to mammals. Six members of this family of proteins have been characterized （LASS1, LASS2, LASS3, LASS4, LASS5 and LASS6） and they all are involved in sphingolipid synthesis. LASS6 is a widely expressed 384 amino acid endoplasmic reticulum, multi-pass membrane protein. On the luminal side of the endoplasmic reticulum membrane, the N-terminal asparagine residue is glycosylated. In cells deficient for CLN9, LASS6 corrects growth and apoptosis, and increases the levels of short ceramide species, such as C14：0- and C16：0-ceramides.
