traveling and attending the opera. She continued to make important scientific contributions after her retirement. One of her passions during this time was encouraging other women to pursue a career in science. Gertrude Elion died in North Carolina in 1999, aged 81. Career and research While Elion had many jobs to support herself and put herself through school, Elion had also worked for the National Cancer Institute, American Association for Cancer Research, and World Health Organization, among other organizations. From 1967 to 1983, she was the Head of the Department of Experimental Therapy for Burroughs Wellcome. She officially retired from Burroughs and Wellcome in 1983. She was affiliated with Duke University as Adjunct Professor of Pharmacology and of Experimental Medicine from 1971 to 1983 and Research Professor from 1983 to 1999. During her time at Duke, she focused on mentoring medical and graduate students. She published more than 25 papers with the students she mentored at Duke. Even after her retirement from Burroughs Wellcome, Gertrude continued almost full time work at the lab. She played a significant role in the development of AZT, one of the first drugs used to treat HIV and AIDS. She also was crucial in the development of Nelarabine, which she worked on until her death in 1999. Rather than relying on trial-and-error, Elion and Hitchings discovered new drugs using rational drug design, which used the differences in biochemistry and metabolism between normal human cells and pathogens (disease-causing agents such as cancer cells, protozoa, bacteria, and viruses) to design drugs that could kill or inhibit the reproduction of particular pathogens without harming human cells. The drugs they developed are used to treat a variety of maladies, such as leukemia, malaria, lupus, hepatitis, arthritis, gout, organ transplant rejection (azathioprine), as well as herpes (acyclovir, which was the first selective and effective drug of its kind). Most of Elion's early work came from the use and development of purine derivatives. Elion's research contributed to the development of: Mercaptopurine (Purinethol), the first treatment for leukemia, also used in organ transplantation. Azathioprine (Imuran), the first immuno-suppressive agent, used for organ transplants. Allopurinol (Zyloprim), for gout. Pyrimethamine (Daraprim), for malaria. Trimethoprim (Proloprim, Monoprim, others), for meningitis, sepsis, and bacterial infections of the urinary and respiratory tracts. Acyclovir (Zovirax), for viral herpes. Nelarabine for cancer treatment. Selected works by Gertrude B. Elion “Interaction of Anticancer Drugs with Enzymes.” In Pharmacological Basis of