APOC3 has been shown to stimulate VLDL synthesis and secretion in cultured cells7 and elevated circulating APOC3 levels correlate with VLDL production8 and postprandial hyperlipidemia in humans.9 Consistent with these findings, we observed an ≍70% increase in VLDL-triglyceride production in ApoC3Tg mice fed a RC diet (Fig. 5A,B), which was associated with marked increases in circulating apoB48 concentrations in ApoC3Tg mice (Fig. 5C). This evidence concerns the gene APOC3 and hyperlipidemia.