APOC4 (apolipoprotein C4) is a member of the apolipoprotein gene family located within the APOE/APOC1/APOC2 cluster on chromosome 19 1. The gene encodes a 127-amino acid protein with a signal peptide and two putative amphipathic α-helical domains characteristic of apolipoproteins 1. APOC4 is predominantly associated with very-low-density lipoprotein (VLDL) particles and plays a role in triglyceride metabolism and lipid homeostasis 2. Genetic variation in APOC4, particularly the Leu36Pro and Leu96Arg polymorphisms, shows significant association with plasma triglyceride levels in women 2. The APOC4 rs1132899 C allele and CC genotype are associated with increased premature coronary artery disease risk, particularly in males 3. APOC4 participates in a regulatory axis controlling lipid metabolism; the NEAT1/hsa-miR-372-3p/AGPS/APOC4 axis regulates triglyceride accumulation and represents a potential therapeutic target for rapamycin-induced dyslipidemia 4. Recent multi-omics analysis identified APOC4 among evolutionarily conserved apolipoproteins enriched in liver and vascular tissues, linking it to metabolic dysfunction-associated steatotic liver disease pathogenesis 5. APOC4 expression is also associated with follicular maturation in reproductive aging 6.