Table 1.

Viral gene expression in Epstein-Barr virus (EBV) associated tumours

Tumour	Latent gene expression	Pattern of latency
BL, endemic	EBNA1	I
BL, sporadic/AIDS	EBNA1	I
Undifferentiated NPC	EBNA1; LMPs 1, 2	II
Hodgkin's disease	EBNA1; LMPs 1, 2	II
T lymphomas	EBNA1; LMPs 1, 2	II
Immunoblastic lymphomas	EBNAs 1–6;	III
	LMPs 1, 2	III

Note that all EBV positive tumours express the EBER RNAs and the BamHIA transcripts. Preliminary work suggests that another form of latency exists with expression of EBNA1 and LMP2 only, and this is often seen in NPC and gastric adenocarcinomas.

BL, Burkitt's lymphoma; EBNA, EBV encoded nuclear antigen; LMP, latent membrane protein; NPC, nasopharangeal carcinoma.