Washington, DC (LifeNews.com) -- Some say the battle over embryonic stem cell research funding is the main source of contention in the stem cell research debate. However, for scientists, it's about patents. The U.S. Patent and Trademark Office has upheld two more patents following a decision in February upholding another.

The Wisconsin Alumni Research Foundation, which holds the original patent on embryonic stem cells, has been a thorn in some scientists' side because it controls how scientists can use the controversial stem cells and how much it costs to use them.

Last month, the USPTO upheld WARF's claims to its main patent and, in a decision released today, the federal agency upheld two more covering scientist James Thomson's work in isolating embryonic stem cells.

According to an AP report, agency officials rejected arguments from two consumer groups and other scientists that Thompson's discovery of human embryonic stem cells was just a natural result of original work on stem cells in animals.

The Foundation for Taxpayer and Consumer Rights and the Public Patent Foundation argue the patenting has driven some scientists overseas because they can't profit from any follow-up work. That say the patents have done more to damage stem cell research in the United States than any lack of state or federal government funding.

"This fight over money illustrates a phenomenon that is too little understood in the country today," bioethics observers Wesley J. Smith said about the decision.

"Science has become a commercial enterprise--even in the ivory covered walls of the university. The days of 'publish or perish' are over. The current mantra is patent or perish," he explained.

Patent challengers say they plan to appeal and fight to make the embryonic stem cells more freely available.

If they fail, the decisions mean the patent holders have the rights to earn royalties on any stem cell research products or treatments that result from research on the stem cells derived under the original patents.

The Wisconsin Alumni Research Foundation handles patents for the scientists at the University of Wisconsin.