To test each of these cell lines for changes in infectability and the involvement of DC-SIGN or DC-SIGNR in infection enhancement, cells were incubated prior to infection with either mannan, which binds to both DC-SIGN and DC-SIGNR, a monoclonal antibody specific for DC-SIGN only (MAB161) or antibody against ICAM-1 as control, which is not known to have a role in KSHV infection, and should not bind either receptor. This evidence concerns the gene CD209 and infection.