Chemotherapy is the treatment of disease with chemicals or drugs and is most commonly associated with treating cancer. The term was first coined in the early 1900s by the German bacteriologist, Paul Ehrlich, after he discovered a dye called Trypan red that combined with and killed trypanosomes, a type of protozoa that caused sleeping sickness. This development earned Ehrlich a share of the Nobel Prize in physiology and medicine in 1908. He also discovered a treatment for syphilis using arsphenamine in 1910. Also during this time, the bone marrow suppressive effect of nitrogen mustard was discovered. Previous attempts to use chemicals to cure disease several centuries earlier failed since there were no methods at that time to determine the causes of disease.

Since Ehrlich's discovery, much progress has been made in developing drugs and chemicals for treating or curing disease. Some of the more famous ones have been antibiotics like...