Compared to the untreated condition, the transfer of viral antigens to uninfected cells was clearly blocked by the neutralizing anti-gp120 mAb IgGb12 (>95% inhibition), but was not inhibited by the RT inhibitor AZT indicating a CD4-dependent transmission of high amounts of HIV-1 particles in the absence of productive infection. The gene discussed is ITIH4; the disease is infection.