HNF4A and infection: In this study, we investigated the potential for lipid metabolism in iHep cells that were directly induced from MDFs by infection with a retrovirus expressing Hnf4α and Foxa3. We found that iHep cells were not only able to synthesize lipids from a cis-unsaturated fatty acid, but also able to accumulate and secrete the synthesized lipids, similar to hepatocytes.