Infectious disease and cancer.

With the recent advances in molecular biology and genetics over the past several decades, we have grad-ually uncovered the elusive cause of some of the malignant diseases that have been, and continue to be, a major factor in human mortality. Infectious disease agents, so ubiquitous in our environment, have now become the most credible link in our search for the cause of cancer. The number of malignancies associated with specific infectious disease agents continues to grow and now represents approximately 20% of all cancers. This perspective represents a brief summary of those cancers that have been associated with or caused by infectious disease agents. Hopefully, knowledge of this relationship can be translated into more effective means of treatment.