Chemotherapy is a by-product of the mustard gas used in WW1.
What Is Mustard Gas?
Mustard gas, in chemical warfare, a liquid agent that blisters the skin and mucous membranes upon direct contact. It has a faint garlic or mustard odour. Despite its name, mustard gas is technically a liquid and forms a mist of small droplets in the air when released.As a result of research conducted in the 1940s, chemicals derived from mustard gas, such as sulfur mustard and nitrogen mustard, were used in chemotherapy to treat cancer; several such chemotherapy medications are still in use, including mustargen, also known as mechlorethamine. Research for other medical uses of mustard compounds continued well into the 1970s.