After Larry Keefer received his B.A. and Ph.D. degrees from Oberlin College (1961, chemistry) and the University of New Hampshire (1965, organic chemistry, mentor Gloria G. Lyle), respectively, he held research positions at the Chicago Medical School and the University of Nebraska College of Medicine before coming to the National Cancer Institute (NCI) in 1971. He and his colleagues in the NCI's Chemistry Section, Laboratory of Comparative Carcinogenesis, are intensively studying the chemistry and pharmacology of the diazeniumdiolates (also known as NONOates) as sources of nitric oxide and nitroxyl for biomedical applications.