APOA5 is an apolipoprotein that plays an important role in regulating the plasma triglyceride levels, a major risk factor for coronary artery disease. It is a component of high density lipoprotein and is highly similar to a rat protein that is upregulated in response to liver injury. Mutations in this gene have been associated with hypertriglyceridemia and hyperlipoproteinemia type 5. This gene is located proximal to the apolipoprotein gene cluster on chromosome 11q23. Alternatively spliced transcript variants encoding the same protein have been identified. Recombinant human APOA5 protein, fused to His-tag at N-terminus, was expressed in E.coli .