Overexpression of various genes and cholesterol efflux in vivo. RAW 264.7 macrophages were transfected with mock (M), ABCA1 (A), ABCA1 + SR-BI + PLTP+ CYP27A1 (A+), ABCG1 (G), caveolin-1 (C), or caveolin-1+ SR-BI (C+), loaded with cholesterol, labeled with [3H]cholesterol, and injected intraperitoneally into mice. The appearance of label in plasma (A), liver (B), and feces (C) was assessed after 24 h as described in Materials and Methods. Means ± SEM (n = 6) are shown; * P < 0.01 versus mock-transfected.