HHV-8, also known as Kaposi's sarcoma-associated herpesvirus (KSHV), is prevalent in immuno-suppressed individuals, such as people who have had an organ transplant and are taking immuno-suppressing drugs, and those with HIV. This virus causes Kaposi's sarcoma, a cancer commonly occurring in AIDS patients, as well as primary effusion lymphoma and some types of multicentric Castleman's disease. It is one of seven currently known human cancer viruses, or oncoviruses. HHV-8 gp64 is a glycoprotein that is located on the surface of the HHV-8 virion envelope.