Apolipoprotein H (ApoH), also known as β2-glycoprotein I, is a multifunctional lipoprotein encoded by the APOH gene in humans. It is a glycoprotein synthesized by hepatocytes, and one of its functions is lipid binding. ApoH can bind to various negatively charged substances such as heparin, phospholipids, and sulfated polysaccharides. ApoH is involved in the complex process of coagulation and can alter ADP-mediated platelet aggregation. It binds to phospholipids on the surface of damaged cells, thereby inhibiting the activation of the intrinsic coagulation cascade. Typically, ApoH in the serum exhibits anticoagulant activity by inhibiting clotting factors. Its plasma concentration is closely associated with changes in metabolic syndrome and vascular complications in type 2 diabetes, making it a clinical marker for assessing cardiovascular risk.