Updated publication reference for PubMed record(s): 32591337. Cholesteryl ester transfer protein (CETP) transfers cholesteryl ester (CE) and triglyceride (TG) between lipoproteins, which alters lipoprotein metabolism. Hamster and human CETPs have very different preferences for CE versus TG as substrate. To assess the impact of altering CETP’s substrate preference on lipoproteins in vivo, human CETP was expressed in hamsters (Mesocricetus auratus). Chow-fed hamsters received adenoviruses expressing no CETP (Ad-Null), hamster CETP (Ad-hamster CETP) or human CETP (Ad-human CETP). High density lipoproteins were isolated from hamster plasma 6 days after adenovirus injection by ultracentrifugation as the 1.063 - 1.21 g/ml density fraction. HDL proteins were precipitated with cold acetone and subjected to LC+MS/MS analysis