Why do we age? Science didn't really start investigating that question until the 1960's.
If you’ve ever seen movies about World War I, you know that the soldiers in the trenches often wore bulbous gas masks that made them look like human insects. The masks were necessary to protect them from chemical weapons such as chlorine gas, a noxious substance that could almost instantly suffocate unprotected victims.
Learn about how chemotherapy drugs work to fight cancer.