LASS3 is a 383 amino acid membrane protein almost exclusively expressed in testis, suggesting that LASS3 plays an important role in proper testis function. It is also weakly expressed in skin. A transcriptional variant of LASS3 cDNA exists and can result in the production of a 419 amino acid protein (LASS3-long). LASS3 overproduction raises the level of several ceramide species, including C18:0- and C24:0-ceramides.