The University of California (UC), the University of Vienna and Emmanuelle Charpentier have filed an appeal to overturn a decision by the US Patent and Trademark Office's Patent Trial and Appeal Board (PTAB), which ruled that patents covering the use of CRISPR–Cas9 in a cellular setting, issued to the Broad Institute, Harvard University and the Massachusetts Institute of Technology, did not interfere with patent applications filed by the UC group. In February the PTAB found that although UC's patent application and the Broad's patents and patent application overlapped in scope, the claims in the interference are separately patentable. The appeal by the UC group, filed on April 12 in the US Court of Appeals for the Federal Circuit in Washington, seeks to have the PTAB reinstate the interference. The UC group's appeal will be bolstered by a recent decision by the European Patent Office (EPO). In March, the EPO said it would grant a patent covering the broad use of CRISPR–Cas9 in both cellular and non-cellular settings to Dublin-based ERS Genomics, the University of Vienna and UC, a finding that puts the EPO at odds with the USPTO. Charpentier is a cofounder of ERS Genomics, which holds the rights to her intellectual property covering all CRISPR applications other than human therapeutics. “It is gratifying to see the EPO recognize with this broad patent the contributions of Dr. Charpentier and her colleagues on the invention of this important technology,” said Eric Rhodes, CEO of ERS. “[W]e are hopeful that we can expect similar outcomes throughout the roughly 80 countries that use a first-to-file system like Europe.”