Therefore, in this study, we aim to investigate the anti-HCV therapeutic potential of AvFc in in vitro neutralization assays and an in vivo HCV challenge study using PXB mice (PhoenixBio Co., Japan), a chimeric urokinase plasminogen activator/severe combined immunodeficiency (uPA/SCID) mouse model transplanted with human hepatocytes (reviewed by Tateno and Kojima25). Here, PLAU is linked to severe combined immunodeficiency.