KAPOSI SARCOMA–ASSOCIATED human herpesvirus, or human herpesvirus 8 (HHV-8), DNA sequences were first identified in 1994 using representational difference analysis on Kaposi sarcoma (KS) and healthy tissue from a patient seropositive for the human immunodeficiency virus (HIV).1 Until now, HHV-8 has been definitively associated with 3 human diseases: KS, primary effusion lymphoma (PEL) (also called body cavity–based lymphoma),2 and multicentric Castleman disease.3