Modern biotherapy has been in use for some 30 years. The first types of biotherapy were nonspecific stimulators of the immune response, but advances in genetic engineering are allowing the mass production of pure biological products which are now being tested as pharmaceutical agents. Biotherapy connotes the administration of products (1) that are coded by the mammalian genome; (2) that modify the expression of mammalian genes; or (3) that stimulate the immune system. In this chapter the discussion of the immune system will be limited primarily to topics relevant to cancer or autoimmune diseases. Because understanding the new biological agents requires an understanding of both the immune response and the molecular basis of oncogenesis, this chapter first presents a summary of the structure and function of the immune system. Following a discussion of immune responses, and the cells involved in these responses, will be a discussion on the current concepts of oncogenesis, particularly oncogenes and growth factors. Because research efforts are beginning to identify many biological proteins as having a role in autoimmune and other diseases, a brief introduction to autoimmune diseases is also included at the end of the chapter
