South San Francisco, California
January 15, 2002

Catalogue of more than 250,000 plant lines creates near complete coverage of plant genome

Agrinomics LLC, a 50/50 research joint venture between Exelixis Plant Sciences and Aventis CropScience (NYSE: AVE), has characterized and catalogued more than 250,000 lines of the plant species Arabidopsis thaliana, identifying nearly its entire genome in less than 18 months and exceeding a key second-year milestone.

The collection of transgenic Arabidopsis allows Agrinomics to rapidly identify genes that play important roles in crop improvement and thus can enhance plant breeding.

"Agrinomics has developed one of the largest Arabidopsis gene libraries in the world, which will be an important tool for the discovery of new and valuable genes and their respective traits," said Lloyd M. Kunimoto, CEO of Agrinomics and Senior Vice President, Corporate Development, Exelixis. "This achievement demonstrates the efficiency and productivity of this joint venture as well as its potential to provide extremely important leads for significant improvements in a very large commercial seed and crop protection market."

Agrinomics has developed a robust gene discovery platform using the model plant species Arabidopsis, a cruciferous species related to canola (spring oilseed rape). The platform relies on a proprietary trait identification method known as Activation Tagging (ACTTAG(TM)), a technique unique to phenotype-directed gene discovery in plants, that enables researchers to rapidly discover genes and the traits they confer, such as disease or insect resistance, herbicide tolerance or improved nutritional qualities.

The Arabidopsis collection is fully indexed and archived using bar-coding and electronic data capturing. Each Arabidopsis line is held separately to facilitate rapid analysis for numerous traits and for the identification of genes responsible for those traits. The results of the screening are recorded and stored in a fully searchable web-based database that includes plant images as well as information on dozens of plant traits for ACTTAG(TM) lines. The entire collection is available for third party partners under conditions negotiated with Agrinomics.

About Agrinomics:

Agrinomics LLC conducts research, development and commercialization programs in the field of agricultural functional genomics. Headquartered in Portland, Oregon, the company is a joint venture between Exelixis Plant Sciences -- a wholly owned subsidiary of Exelixis, Inc. -- and Aventis CropScience formed in July 1999 to identify, develop and commercialize novel traits using the Arabidopsis ACTTAG(TM) Gene Discovery Program.

About Exelixis and Exelixis Plant Sciences:

Exelixis, Inc. is a leading genomics-based drug discovery company focused on product development through its expertise in comparative genomics and model system genetics. These technologies provide a rapid, efficient and cost-effective way to move from DNA sequence data to knowledge about the function of genes and the proteins they encode. The company's technology is broadly applicable to all life sciences industries including pharmaceutical, diagnostic, agricultural biotechnology and animal health. Exelixis has partnerships with Aventis CropScience, Bayer, Bristol-Myers Squibb, Elan Pharmaceuticals, Pharmacia, Protein Design Labs, Schering-Plough Research Institute, Scios Inc., Dow AgroSciences and Cytokinetics, Inc. and is building its internal development program in the area of oncology.

Located in Portland, Oregon, Exelixis Plant Sciences is focused on the use of model plant systems such as Arabidopsis, tomato and rice as tools for gene discovery that will lead to improvement in crops for human and animals, as well as improved crop protection. Exelixis formed Exelixis Plant Sciences in December 2000, after acquiring Agritope, Inc., in order to expand its access to plant model system technologies and product development.

About Aventis CropScience

Aventis CropScience is a major crop protection and crop production company, which is also involved in top ranking environmental and public health activities. With 2000 sales of 4,034 million Euros, Aventis CropScience devotes over 11% of its turnover to the Research and Development of new chemicals, biotechnology and plant varieties. It employs about 14,400 people in more than 120 countries worldwide.