Researchers at the National Institute of Allergy and Infectious Disease (NIAID), a component of the National Institutes of Health (NIH), have identified a critical human cell surface molecule involved in infection by Kaposi’s sarcoma herpesvirus (KSHV), the virus that causes Kaposi’s sarcoma and certain forms of lymphoma. Kaposi’s sarcoma is a major cancer associated with HIV/AIDS, and it typically manifests as multiple purple-hued skin lesions.