EXHIBIT 10.1 March 31, 2003 VIA FEDERAL EXPRESS Dr. Robert J. Lefkowitz Duke University Medical Center Box 3821 Durham, North Carolina 27710 Dear Bob: We are delighted that you, an investigator of the Howard Hughes Medical Institute (the "Institute")...Consulting Agreement • May 9th, 2003 • Lexicon Genetics Inc/Tx • In vitro & in vivo diagnostic substances • Texas
