The U.S. government, which formerly allowed genes to be patented, has now reversed its position, stating that genes should not be eligible for patents because they are part of nature. The Department of Justice filed a brief on Friday in its capacity as a friend of court in a case dealing with human genes linked to breast and ovarian cancer. In March, a district court judge ruled in the case that the two patents which had been held by Myriad Genetics and the University of Utah, are invalid. It is unclear whether or not the U.S. Patent and Trademark Office will implement this extreme policy change, having already issued thousands of patents on genes, including approximately twenty percent of human genes. If the Patent Office discontinues issuing patents on genes, it is likely to provoke the ire of biotechnology companies, who state that gene patenting is essential in the development of personalized medicine.