Thanks to the impressive development and application of new sophisticated technologies, the last decade has offered remarkable advances in our understanding of the molecular and biological features of human neoplastic cells. DNA analysis in particular has contributed to the unravelling of some of the possible events which give rise to a transformed cell and which enable it to proliferate indiscriminately and to infiltrate. Cloning techniques which have allowed researchers to obtain and utilize purified molecules represent another milestone. This has opened the era of cytokines and growth factors, both in terms of their possible role in the establishment and/or progression of neoplastic conditions (autocrine/paracrine models) and of their use in clinical practice. Thus, growth factors such as granulocyte-macrophage colony stimulating factors (GM-CSF) and interleukin 3 (IL-3) are currently being employed in the management of cancer patients, mainly to support normal hemopoiesis. Conversely, recombinant interleukin 2 (IL-2) through its unique capacity to generate previously unrecognized cytotoxic activity, lymphokine active killer (LAK), has brought about new and more specific immunotherapeutic strategy. Further therapeutic possibilities will arise from the clinical use of monoclonal antibodies. Finally, the development of genetic engineering has opened the way to the early and revolutionary clinical exploitation of gene therapy; the possibility of utilizing in vivo anti-sense oligonucleotides in an attempt to block the action of specific genes is also being contemplated.(ABSTRACT TRUNCATED AT 250 WORDS)