ZAMENHOF, STEPHEN (1911–1998), U.S. biochemist. Born in Warsaw, the nephew of Ludwik *Zamenhof, he went to the U.S. in 1939. He worked at Columbia until 1964, when he became professor of microbial genetics and biological chemistry at the School of Medicine of the University of California at Los Angeles. His 250 scientific papers were concerned with nucleic acids, enzymes, growth hormones, immunology, and genetics. He wrote The Chemistry of Heredity (1959).