Surprisingly, alteration of a single residue (V210G, ah4) allowed human TfR1 to efficiently support the entry of TCRV pseudovirus, while replacement of four residues in this loop with the corresponding residues of NsTfR1 (nh5) was necessary to support efficient infection by AMAV pseudovirus (Figure 6D and 6E). This evidence concerns the gene TFRC and infection.