['We examined the effect of ezetimibe, a cholesterol absorption (CA) inhibitor, and genetic determinants of CA on reverse cholesterol transport (RCT) from subcutaneously injected macrophages using a new dual isotope label technique.', 'Treatment of C57BL/6J mice with ezetimibe decreased dietary CA by 86% and increased RCT from peripheral tissue macrophages (PTM) by 6-fold (P<0.0001). Moreover, congenic 14DKK mice with a modest 41% decrease in dietary CA displayed a 67% increase in RCT from PTM (P<0.007).'] Is cholesterol absorption from the intestine a major determinant of reverse cholesterol transport from peripheral tissue macrophages?