GTC BIOTHERAPEUTICS REGAINS COMPLIANCE WITH NASDAQ MARKETPLACE RULE 5550

FRAMINGHAM, MA – May 12, 2009 -- GTC Biotherapeutics, Inc. ("GTC" or “the Company”, NASDAQ: GTCB) received notice from the Listing Qualifications Staff (“Staff”) of The NASDAQ Stock Market indicating that GTC has regained compliance with the minimum market value of listed securities requirement for continued listing on The NASDAQ Capital Market, as set forth in Marketplace Rule 5550 (b)(2), by exceeding $35 million of market capitalization for 10 consecutive trading days.

About GTC Biotherapeutics

GTC Biotherapeutics develops, supplies and commercializes therapeutic proteins produced through transgenic animal technology. ATryn®, GTC’s recombinant human antithrombin, has been approved for use in the United States and Europe. ATryn is the first and only product produced in transgenic animals to be approved for therapeutic use anywhere in the world. In addition to ATryn, GTC is developing a portfolio of recombinant human plasma proteins with known therapeutic properties. These proteins include recombinant forms of human coagulation factors VIIa and IX, which are being developed for the treatment of hemophilia. GTC is also developing a portfolio of follow-on biologic monoclonal antibodies and a CD20 antibody with enhanced ADCC (antibody-dependent cell-mediated cytotoxicity). GTC’s intellectual property includes a patent in the United States through 2021 for the production of any therapeutic protein in the milk of any transgenic mammal. GTC’s transgenic production platform is particularly well suited to enabling cost effective development of proteins that are difficult to express in traditional recombinant production systems as well as proteins that are required in large volumes. Additional information is available on the GTC web site, http://www.gtc-bio.com.

CONTACT:
GTC Biotherapeutics, Inc.
Thomas E. Newberry
Vice President, Corporate Communications and Government Relations
(508) 370-5374 or tom.newberry@gtc-bio.com