ERVW-1 and infection: As observed for the other rVSVs that we generated in previous studies [25,41,48,49], in vitro infection with G-complemented VSVΔG-JmGL-AcGFP clearly reduced the number of STLV-1 Env-expressing cells, most likely through virus-mediated membrane fusion following receptor–Env binding, whereas infection with the control virus, G-complemented VSVΔG-AcGFP, did not (Figure 4B).