William Cumming Rose was an American biochemist and nutritionist. He discovered the amino acid threonine and his research determined the requirement for essential amino acids in diet. William Cumming Rose was born on April 4, 1885 in Greenville, South Carolina. Rose obtained his B.S. degree and went to Yale University and the Sheffield Scientific School. There he studied biochemistry and worked as an assistant in the laboratory of Layfayette Mendel. In the late 1930s Rose was responsible for a beautifully precise set of experiments that introduced the idea of an essential amino acid into nutrition, demonstrating its effect on both human and rodent diet. He was granted a Ph.D. in 1911. He received the National Medal Of Science in 1966. Rose died on September 15, 1985.