The Woodlands, Texas, May 31, 2005 - Lexicon Genetics Incorporated (Nasdaq: LEXG) announced today that Brian P. Zambrowicz, Ph.D., Lexicon's executive vice president of research, will present at the Pacific Growth Equities Life Sciences Growth Conference at InterContinental Mark Hopkins Hotel in San Francisco, California on Tuesday, June 7, 2005 at 9:00 a.m. Pacific Time.  Dr. Zambrowicz will provide an overview of Lexicon and discuss its drug discovery and development programs and collaborations.
 
A live webcast of Dr. Zambrowicz' presentation may be accessed on Lexicon's corporate website at www.lexicon-genetics.com.  An archived version of the webcast will be available on the website through June 15, 2005.

About Lexicon Genetics

Lexicon Genetics is a biopharmaceutical company focused on discovering and developing new ways to treat human disease.  Using its proprietary gene knockout technology, Lexicon is systematically discovering the physiological and behavioral functions of genes to identify potential points of therapeutic intervention, or drug targets.  Lexicon has advanced knockout-validated targets into small molecule and biotherapeutic drug discovery programs in six therapeutic areas:  diabetes and obesity, cardiovascular disease, psychiatric and neurological disorders, cancer, immune system disorders and ophthalmic disease.  Lexicon is working both independently and through strategic alliances to accelerate the development and commercialization of its discoveries.  Additional information about Lexicon is available through its corporate website, www.lexicon-genetics.com.

Lexicon Genetics Safe Harbor Statement

This press release contains "forward-looking statements," including statements about Lexicon's growth and future operating results, discovery and development of products, strategic alliances and intellectual property, as well as other matters that are not historical facts or information.  These forward-looking statements are based on management's current assumptions and expectations and involve risks, uncertainties and other important factors, specifically including those relating to Lexicon's ability to successfully conduct preclinical development of its drug candidates and advance such candidates into clinical development, achieve its operational objectives, obtain patent protection for its discoveries and establish strategic alliances, as well as those relating to manufacturing, the regulatory process, intellectual property rights, and the therapeutic or commercial value of its drug candidates, that may cause Lexicon's actual results to be materially different from any future results expressed or implied by such forward-looking statements. Information identifying such important factors is contained under "Factors Affecting Forward-Looking Statements" and "Business - Risk Factors" in Lexicon's annual report on Form 10-K for the year ended December 31, 2004, as filed with the Securities and Exchange Commission.  Lexicon undertakes no obligation to update or revise any such forward-looking statements, whether as a result of new information, future events or otherwise.