Any virus that can produce a cancer in an organism.
A virus that causes malignant neoplasms. Viruses suspected of causing tumors in humans include Epstein-Barr virus (associated with Burkitt’s lymphoma), hepatitis B virus (with hepatocellular carcinoma), papilloma virus (with carcinoma of the cervix), and human herpesvirus 8 (with Kaposi’s sarcoma).