Table 1.

Human tumor viruses.

Virus	Family	Genome	Year Discovered	Cell type targeted	Associated Cancer(s)	References
RNA Viruses
Human T-lymphotropic virus-1 (HTLV-1)	Retroviridae	+ssRNA	1980	T cells	Adult T cell leukemia	[304]
Hepatitis C virus (HCV)	Flaviviridae	+ssRNA	1989	Hepatocytes	Hepatocellular carcinoma, lymphoma	[305]
DNA Viruses
Epstein-Barr virus (EBV)	Herpesviridae	dsDNA	1964	B cells, epithelial cells, T and NK cells	Burkitt's lymphoma, nasopharyngeal carcinomas, lymphoproliferative diseases	[4]
Hepatitis B virus (HBV)	Hepadnaviridae	ssDNA, dsDNA	1965	Hepatocytes	Hepatocellular carcinoma	[306]
Human papillomavirus (HPV16, HPV18)	Papillomaviridae	dsDNA	1983–84	Keratinocytes	Cervical cancer and other anogenital cancers, oropharyngeal cancer	[55,56]
Kaposi's sarcoma herpesvirus (KSHV)	Herpesviridae	dsDNA	1994	B cells, endothelial cells	Kaposi's sarcoma, primary effusion lymphoma	[307]
Merkel cell polyomavirus (MCPyV)	Polyomaviridae	dsDNA	2008	Keratinocytes?	Merkel cell carcinoma	[82]
				Fibroblasts?
				Merkel cells?