The KSHV envelope glycoproteins play key roles not only in virion binding to the host cell plasma membrane associated molecules (receptors) and subsequent entry during primary target cell infection, but also in the complex process of nuclear assembly of enveloped viral particles, re-envelopment in the cytoplasmic vesicles and egress of the progeny virus during a lytic infection. The gene discussed is ERVW-1; the disease is infection.