Mouse bone marrow-derived mesenchymal stem cells (mMSC) were obtained from Life Technologies (Grand Island, NY) and grown in Dulbecco’s Modified Eagle Medium (DMEM)/Nutrient Mixture F-12 containing MSC-Qualified FBS (Gibco, Grand Island, NY). Human bone marrow-derived mesenchymal stem cells (hMSC) were obtained as previously described.21 (link)–24 (link) Non-malignant human hepatocytes (HH) were obtained from Sciencell (Carlsbad, CA) and cultured as recommended by the supplier.