Hfe-/- and Hfe+/+ mice (five males per group) were killed at age 7 weeks. Blood was removed and plasma lipid levels were determined by chromatography. Results are expressed as mean ± standard deviation in each group. P values for comparisons of plasma lipid levels between Hfe-/- and Hfe+/+ mice of each strain were obtained by Student's t-test. HDL, high-density lipoprotein.