We can hypothesize that apoC1 may have different functions according to its distribution between lipoproteins (with a pro-atherogenic effect when associated with VLDL and an anti-atherogenic effect when associated with HDL) and that qualitative changes of apoC1 occurring in clinical situations as diabetes and atherosclerosis may also modify its properties and expression pattern. This evidence concerns the gene APOC1 and atherosclerosis.