A great deal of new information has been obtained during the past four years, and this monograph provides a clear and well reviewed update on biochemical mechanisms and the results of important new clinical studies using the interferons. Reviews include what is presently known about the biosynthesis, physiological role and mechanisms of action of the interferons (alpha, beta, gamma). New biochemical information on interferon-receptor interactions and signalling pathways is provided. The pharmacokinetic considerations in treating leukemia, lymphoma, myeloma, neuroendocrine tumors and other solid tumors are reviewed with special emphasis on studies of adjuvant chemotherapy in malignancies of the immune system.