The Wisconsin foundation that holds several key embryonic stem cell patents said Thursday that it has received certificates signaling the end of a long-fought challenge to the patents.
The Wisconsin Alumni Research Foundation, known as WARF, received the so-called re-examination certificates from the U.S. Patent and Trademark Office this week, WARF spokeswoman Janet Kelly said. The certificates confirm the patent officeâ??s ruling in March to strike down a challenge to the patents that started in October 2006.