As Science put it in a story  on the issue:
Any competent graduate student can take a known protein and come up with the nucleotide sequence that encodes it. Does that mean the gene’s code is obvious, in a legal sense, and therefore cannot be patented?
On Friday, in a little-noticed ruling  likely to make biotech patents harder to obtain in the future, a federal appeals court in Washington, D.C., answered with a definitive yes.
The court declared that an invention owned by Amgen Inc. in Thousand Oaks, California, was so obvious as to be unpatentable. The invention, first discovered by scientists at Immunex near Seattle, Washington, and then sold to Amgen, was the sequence of a gene for the protein NAIL, important in the human immune response. But those who opposed the patent argued that it took no original insight to work out the gene's code. The U.S. Court of Appeals for the Federal Circuit agreed with the skeptics. The judges backed a decision made earlier by the U.S. patent office (in a case known as In re Kubin ), dismissing what the court called an "alleged discovery." The court's ruling is one of many signs that claims based on gene sequences are getting much tougher scrutiny now than in the past.