Kaposi's Sarcoma-Associated Herpesvirus (KSHV), also known as Human Herpesvirus 8 (HHV-8), is a oncogenic virus that is primarily associated with Kaposi's Sarcoma (KS), a type of cancer that forms in the lining of blood and lymph vessels. This virus is part of the Herpesviridae family and can remain latent in the host cells for a long period.