The latent membrane protein 1 (LMP1) of Epstein-Barr virus is a viral oncogene with the potential to antagonize apoptosis and senescence as well as to promote cellular survival and proliferation. LMP1 acts like a constitutively active receptor recruiting signalling molecules typically employed by the cellular tumour necrosis factor-receptor (TNF-R) and Toll-like/interleukin-1-receptor (TIR) families. LMP1 activates the classical and alternative NF-jB pathways, c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein kinase (MAPK), the JAK/STAT and phosphatidylinositol 3-kinase (PI3K) pathways. In this article, interactions of LMP1 with host cell signal transduction pathways and their role in LMP1-induced cell transformation are reviewed.