Cancer Progression Goes Viral: The Role of Oncoviruses in Aggressiveness of Malignancies

Cancer progression is the most relevant phase of carcinogenesis due to the development of malignant tumors in the host. Some viruses participate in malignant cell transformation, with recent compelling evidence suggesting that oncoviruses also have a role in cancer progression. The human hepatitis B (HBV) and C (HCV) viruses, human papillomaviruses (HPV), Epstein-Barr virus (EBV), and Kaposi sarcoma herpesvirus (KSHV) are the most important human oncoviruses currently known. Here, we discuss how oncoviruses can modulate cancer progression, such as tumor growth, invasion, and cancer metastasis.