The top appeals board of the European Patent Office has ruled that transgenic plants may be patented under the European Patent Convention. In late December, the Patent Office's Enlarged Board of Appeal, considering an appeal by Novartis, ruled that article 53b of the Convention, which excludes plant and animal varieties from patenting, does not apply to plant types in general that are modified by patentable biotechnological processes. Last September, a new Convention regulation came into effect that brought interpretation of article 53b in line with the European Union's directive on the patenting of biotechnology inventions concerning genetically modified organisms. But the Patent Office has been awaiting the Enlarged Board of Appeal's decision on the Novartis appeal before implementing the new rules (Nat. Biotechnol . 17, 842, 1999).