June 5, 2001 -- On May 30, 2001, the United States Court of Appeals for the Federal Circuit ruled that Mycogen Plant Science, Inc. is entitled to continue a biotechnology-related patent infringement suit
against Monsanto Company. The Mycogen patent at issue covers a process for increasing the expression of Bacillus thuringiensis (Bt) insect resistance traits in crops.

In its decision, the Federal Circuit ruled that the United States District Court for the Southern District of California erred when it found that Mycogen's patent was invalid and granted summary judgment in favor of Monsanto. The
case has now been returned to the district court where it will proceed.

"This victory for Mycogen is extremely significant," says Guy Relford, Dow AgroSciences global legal counsel for litigation. "Mycogen's patent covers a process for synthesizing a Bt gene to attain commercially valuable
levels of insect control in crops. We believe that virtually every company engaged in the development of Bt products is utilizing Mycogen's patented process."

For more information, visit the Mycogen Web site.