To initiate the inquiry into how cyp27a1 production of 27HC in macrophages (Fig. 1a) influences atherosclerosis, we first determined that both 27HC content and cyp27a1 expression are increased in the aortas of hypercholesterolemic apoE-/- mice compared to those of normocholesterolemic standard chow-fed wild-type mice (Fig. 1b, c, Supplementary Fig. 1a). The gene discussed is APOE; the disease is atherosclerosis.