Liver fibrosis occurs in several genetic and acquired disease conditions, leading to alterations of the tissue and metabolism, which may adversely affect viral vector-mediated gene therapy. Here, we assessed the impact of liver fibrosis on in vivo gene transfer to hepatocytes mediated by lentiviral vectors or adeno-associated viral vectors. We exploited two chemically induced fibrosis mouse models characterized by tissue damage in different areas of the liver lobule. Moreover, we used Abcb11