MADISON, Wis. -- After scientist Jamie Thomson isolated human embryonic stem cells in 1998, colleagues said that he had opened the door to novel medical treatments that would transform science.

The University of Wisconsin-Madison biologist appeared on the cover of Time Magazine under the headline: "The man who brought you stem cells."

But nearly a decade later, some scientists are dismissing Thomson's work as obvious and asking the federal government to revoke patents on his work. These scientists argue that any researcher with Thomson's funding and access to human embryos could have done the same thing.

The Wisconsin Alumni Research Foundation (WARF) is defending the patents and Thomson's work. The U.S. Patent and Trademark Office will ultimately decide whether to allow the patents to stand.

The outcome could determine Thomson's reputation as a pioneer in the field and whether UW receives millions of dollars in revenue from the patents.