Sphingolipids play essential roles in various cellular events, including proliferation, differentiation, senescence, apoptosis, and inflammatory responses. Serine palmitoyltransferase (SPT) is the initial and rate-limiting enzyme in the de novo sphingolipid biosynthesis, and thus regulates the level of sphingolipids in cells. Immunohistochemical study revealed widespread distribution of the enzyme with most strong expression in brain and digestive tract. Two subunits, SPT1 and SPT2 at a stoichiometry of 1:1, are involved in the enzymatic activity of SPT.Synonyms: LCB 1, LCB1, Long chain base biosynthesis protein 1, SPT 1, SPT1, Serine palmitoyltransferase 1, Serine-palmitoyl-CoA transferase 1