During in vitro foam cell formation, EIIIA mRNA is induced and EIIIA^–/–ApoE^–/– cells accumulate less lipid. (A) RT-PCR of foam cell mRNA at 0, 5, or 24 hours after addition of acetylated LDL. EIIIA-plus and EIIIA-minus mRNA are indicated by EIIIA⁺ and EIIIA^– mRNA, respectively. (B) Differential interference contrast microscopy of macrophages after 72-hour incubation with or without acetylated LDL. Cells were stained with oil red O and counterstained with hematoxylin. (C) Quantification of cholesterol in cells. After 24-hour incubation with native or acetylated LDL, cells were lysed and assayed for total cholesterol and protein. Data presented reflect the means of at least 4 separate experiments. *P < .01, t test. Error bars represent SEM.