GTC BIOTHERAPEUTICS TO HOST FOURTH QUARTER AND YEAR END 2006 EARNINGS CALL AND WEBCAST ON MONDAY, MARCH 5, 2007 Framingham, Mass., February 26, 2007 -- GTC Biotherapeutics, Inc. (Nasdaq: GTCB) ("GTC") announced today that its financial results for the fourth quarter and year end 2006 will be released on Monday, March 5, 2007 before the Nasdaq market opens. Geoffrey F. Cox, Ph.D., Chairman of the Board, Chief Executive Officer and President, will lead the call on March 5 starting at 10:00 a.m. Eastern Time. You may access the live internet broadcast or the subsequent archived recording, on GTC's website at http://www.gtc-bio.com or as follows: Live Call - In the United States, dial 1-866-314-4865 Outside the United States, dial 1-617-213-8050 Reference call ID: when prompted 63614331 Audio Archive - In the United States, dial 1-888-286-8010 Outside the United States, dial 1-617-801-6888 Reference call ID: when prompted 99445437 NOTE: a replay of the call will be available one hour following the end of the call and will be accessible until March 12, 2007. The earnings webcast is also being distributed over CCBN's Investor Distribution Network to both institutional and individual investors. Individual investors can listen to the call through CCBN's individual investor center at www.earnings.com or by visiting any of the investor sites in CCBN's Individual Investor Network. Institutional investors can access the call via CCBN's password-protected event management site, StreetEvents (www.streetevents.com). About GTC Biotherapeutics GTC Biotherapeutics develops, produces, and commercializes therapeutic proteins through transgenic animal technology. In August 2006, ATrynŽ, GTC's recombinant form of human antithrombin, was approved by the European Commission for use in patients with hereditary antithrombin deficiency undergoing surgical procedures. This was the first approval anywhere in the world of a therapeutic protein produced from a transgenic animal. ATrynŽ is in phase III studies to support a filing in the United States requesting approval in the hereditary deficiency indication. In addition, GTC established a strategic collaboration with LFB Biotechnologies of France to jointly develop recombinant forms of human plasma proteins and monoclonal antibodies. The first program of the collaboration will be to develop recombinant human factor VIIa as a potential treatment for hemophilia in patients with antibodies to other coagulation factors. GTC has also recently been granted 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 those 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 (508) 370-5374 Feinstein Kean Healthcare Francesca DeVellis (investors) (617) 577-8110
	Copyright 2007 GTC Biotherapeutics, All Rights Reserved