The Canadian Supreme Court denied a Harvard bid to patent a genetically-engineered mouse last week in a move that has broad implications for research into higher life forms in Canada.

Thursday’s 5-4 decision ended Harvard’s nearly 10 years of legal wrangling to win control over research using the so-called “oncomouse,” which was created by Harvard Medical School scientists in the 1980s. The mouse can help test cancer treatments, since it is engineered to develop tumors that are also found in humans.

Harvard was permitted to patent the mouse in the United States in 1988, and has also done so in Europe, Japan and Australia.

Last week’s denial was based on an 1869 Canadian patent law and an archaic definition of an invention as a “composition of matter.” This wording appears in United States patent law as well and originates with Thomas Jefferson, said David Morrow, the Ottawa lawyer who represented Harvard before the court.

“Higher life forms cannot be conceptualized as mere ‘compositions of matter’ within the context of the [1869] Patent Act,” the decision reads.

The decision counters the argument that “composition of matter” didn’t explicitly include higher life forms simply because that wasn’t a reality for 19th century lawmakers.

“Just because all inventions are unanticipated and unforeseeable, it does not necessarily follow that they are all patentable,” the Canadian court decision reads.

Morrow said he disagreed with the court’s narrow interpretation of the more than 100-year-old wording.

“The problem with this one is that there were definitions that were very old or very general,” Morrow said. “The argument was that ‘composition of matter’ includes a complex, living definition of matter, and that’s where the court disagreed with us.”

Harvard Medical School issued a statement opposing the decision.

“Canadians scientists are at-risk of being left behind their colleagues around the world as a result of this decision,” the statement read.

The Medical School spokesperson declined to comment further.

Medical School geneticist Philip Leder, the co-creator of the oncomouse, declined comment through an assistant.

Morrow said that by limiting the possibility of financial returns, the decision was likely to discourage research into genetically modified organisms.

The Canadian legislature, however, may choose to revise the 1869 law—a move the court decision encouraged. It commissioned a report from the Canadian Biotechnology Advisory Committee that favored granting patents for non-human higher life forms, Morrow said.