ERVW-1 and infection: We found that at least one gp41 glycan (N616) was indispensable for a wild-type-like viral phenotype of HIV-1NL4.3 (efficient cell-free infection, CD4 binding, envelope glycoprotein expression and transmission of DC-SIGN-captured virus to CD4+ T-lymphocytes), and the deletion of two other N-glycans (N611 and N637) also showed decreased infectivity of the corresponding mutant HIV-1NL4.3 strains.