The protective influence of female hormones against atherosclerosis in the apoE-/- mouse is corroborated by the findings that estrogen administered to apoE-/- mice (C57 × 129ola genetic background) prevented fatty streak formation in female and male mice fed a chow diet [31] and reduced atherosclerotic lesion development in mice fed a Western-type diet [33]. This evidence concerns the gene APOE and atherosclerosis.