HIF1A and atherosclerosis: Overexpression of SMPD3 lentivirus and administration of ceramide counteract the benefits of adipocyte HIF-1α deficiency in atherosclerosis.460 Type 2-neutral sphingomyelinase (nSMase2), also known as SMPD3, is situated within membrane structures through the insertion of palmitoylated residues into the lipid bilayer and its interaction with anionic phospholipids.