Neutralization activity of KDEL-tagged (usually high mannose) and non-KDEL- tagged (usually complex) glycoforms of N. b/p19-derived mAb (Fig. 1) was measured in a TZM-bl assay as a reduction in Luc reporter gene expression after a single round of infection with a small panel of Env-pseudotyped viruses, including six Tier 2 HIV-1 isolates (Fig. 1a) and three simian/human HIV (SHIV) isolates (Fig. 1b). This evidence concerns the gene ERVW-1 and infection.