ectopic APOM1 and APOM5 expression. WRL-68 and HepG2 hepatic cell lines were purchased from American Type Culture Collection (Rockville, MD, USA) and maintained in RPMI-1640 medium supplemented with 10% FBS and 100 units/ ml penicillin and 100 mg/ml streptomycin in a humidified atmosphere containing 5% CO 2 at 37uC. Prior to the expreiments measuring cellular and medium cholesterol content, cells were switched to serum free and phenol red free RPMI medium (Invitrogen, Carlsbad, CA, USA).