Experimentally, it has been shown that two human ERV-encoded gamma-type Envs (Suppressyn and Syncytin-1/HERV-W) that bind the ASCT2 receptor (SLC1A5) can also induce receptor-interference and render cells resistant to infection by extant retroviruses of other primates that also use ASCT2 as an entry receptor [25,71]. This evidence concerns the gene ERVW-1 and infection.