2.5. Cell Culture. HepG2 cells, a human hepatocellular carcinoma cell line, A549 cells, a adenocarcinomic human alveolar basal epithelial cells, and NIH3T3 cells, a mouse embryonic fibroblast cell line, were obtained from Riken Bioresource Center (Tsukuba, Japan). HepG2, A549, and NIH3T3 cells were grown in DMEM, containing 1 × 10 5 U/L of penicillin, 0.1 g/L of streptomycin supplemented with 10% FCS at 37 • C in a humidified 5% CO 2 and 95% air atmosphere.