The impressive advances in all branches of medical science during the first half of this century with the discovery of many chemotherapeutic or immunogenic agents gave rise to brilliant achievements in the struggle against some infectious diseases and aroused in many scientists the wishful thought that drugs for cancer therapy would, soon lead to additional great success. Notwithstanding ever-increasing worldwide endeavors, the major problems in prevention or treatment of neoplastic diseases are still unsolved. The approach to the resolution of these problems follows many different pathways. Basic research tries to cast light on the genetic and biochemical processes underly- ing cell division and differentiation as well as the interactions occurring between the cell and the oncogenic stimulus, or between the neoplastic cells and the different body systems endowed with immunological reactivity. Another line of approach, coherent with the classic basis of chemotherapy, relies upon the search for new compounds selectively blocking the multiplication of the neoplastic cells. The remarkable progress made in treating human cancer, as a result of these efforts, has been until now ascribable chiefly to the accomplishment of the chemo- therapeutic approach. Studies on the cytostatic activity of the anthracycline antibiotics carried out over many years eventually led the investigators of Farmitalia (Milan, Italy) to discover and characterize some new compounds endowed with interesting chemotherapeutic properties against malignant neoplastic diseases.