1. Treatment using biological agents, almost always those made by genetic engineering. Genetic engineering is central to modern biotherapy’s backbone: pharmaceutical biotechnology. Pharmaceutical biotechnology involves using microorganisms, macroscopic organisms, or hybrids of tumor cells and leukocytes.
2. Virtually all biotherapeutic agents in clinical use are biotech pharmaceuticals. A biotech pharmaceutical is simply any medically useful drug whose manufacture involves microorganisms or substances that living organisms produce (e.g., enzymes). Most biotech pharmaceuticals are recombinant‹that is, produced by genetic engineering. Insulin was among the earliest recombinant drugs.
3. In psychology, any form of treatment for abnormal behavior that alters the individual’s physiological processes; such as, electric shock treatment or surgery.
4. The treatment of disease with biologicals, that is, materials produced by living organisms.