CERT1 (ceramide transporter 1) is a lipid transfer protein that mediates non-vesicular trafficking of ceramides from the endoplasmic reticulum to the Golgi apparatus 12. The protein harbors a steroidogenic acute regulatory lipid transfer (START) domain that shelters ceramide molecules and preferentially transfers those with long-chain fatty acids, though it exhibits minimal activity toward very long-chain ceramides 23. CERT1 functions through a previously uncharacterized dimeric helical domain that enables homeostatic autoregulation via serine-repeat motif (SRM) hyperphosphorylation; disruption of this mechanism causes unchecked sphingolipid production 4. De novo missense variants in CERT1 cause ceramide transporter (CerTra) syndrome, characterized by intellectual disability, hypotonia, and speech delay, with clinical severity correlating to the degree of disrupted CERT autoregulation 45. Pathogenic mutations impair SRM phosphorylation-dependent repression, rendering CERT excessively active and causing aberrant subcellular redistribution 5. Beyond developmental disorders, plasma ceramide-based risk scores (CERT1) derived from specific ceramide species predict cardiovascular mortality and adverse outcomes independent of traditional risk factors 678, and associate with prevalent rheumatoid arthritis 9.