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....