SGMS1 encodes sphingomyelin synthase 1 (SMS1), the major Golgi-localized enzyme catalyzing sphingomyelin (SM) biosynthesis through reversible phosphocholine transfer from phosphatidylcholine to ceramide 1. The reaction direction depends on intracellular ceramide and diacylglycerol levels 1. SMS1 forms complexes with glucosylceramide synthase, controlling ceramide metabolic fate 1. By regulating both pro-apoptotic ceramide and anti-apoptotic diacylglycerol levels, SMS1 modulates cell survival signals and membrane raft-mediated signaling 2. SGMS1 expression is tissue-specific and regulated through alternative promoters and 5'-UTR variants, with notably elevated expression in brain tissues 3. SGMS1 generates circular RNAs predominantly in brain, containing multiple microRNA-binding sites suggesting post-transcriptional regulatory functions 4. Clinically, SGMS1 shows altered expression in lung cancer (decreased) and esophageal cancer (variable), indicating cancer-type-specific dysregulation 2. Recently, SMS1 emerged as critical for RNA virus replication; SGMS1 knockout inhibited SFTSV, SARS-CoV-2, and LCMV replication in cells 5. A novel SMS1 inhibitor protected mice against lethal SFTSV infection and reduced SARS-CoV-2 pathogenesis, suggesting SMS1 as a broad-spectrum antiviral target 5.