MEF cells derived from ABCG1 or WT mice were differentiated and labeled overnight with 3H-cholesterol (5µCi/mL), equilibrated and then washed with PBS and efflux to apoA-I (20µg/ml), HDL3 (50µg/ml) or 5% serum was monitored over 4h. RNA and protein was extracted. (A) Efflux from WT and ABCG1−/− to ApoA-I, HDL3 and serum. (B) ABCG1 mRNA levels were markedly reduced in ABCG1−/− cells compared with WT control (n=3, ***p<0.001). (C) ABCG1 protein levels were barely detectable in WT and ABCG1−/− MEF adipocytes compared with positive control mouse liver lysate, positive control.