ERVW-1 and infection: Then we tried to identify the residues among eleven mutated amino acids in HCV-JFH1-tau Lot B1 responsible for the CLDN1-independent infection phenotype using an infection system where infection assays are performed by HCV-JFH1-tau encapsidated with exogenously supplemented HCV envelope proteins with mutations (HCVee) (Supplementary Fig. S4a).