A court ruling issued in September brings the fight over who owns the use of CRISPR in eukaryotic cells one step closer to the finish line. The Court of Appeals for the Federal Circuit (CAFC) affirmed an earlier decision giving the Broad Institute ownership of the key patent at issue. In February 2017, a US Patent and Trademark Office appeal board said that the patent granted to the Broad's Feng Zhang, covering the gene editing technology's use in eukaryotic cells, does not interfere with CRISPR intellectual property from the University of California, Berkeley and co-inventors Jennifer Doudna and Emmanuelle Charpentier, which covers its use in cell-free systems, thus rendering both methods as patentable separately (Nat. Biotechnol. 35, 184, 2017). The CAFC's ruling effectively ends Berkeley's challenge to the patent's validity. Berkeley had filed for intellectual property of the technology in May 2012, six months before Zhang, but in April 2014, under a fast-track program, Zhang was issued the first patent. After reviewing the evidence, the CAFC confirmed that it stood by its previous decision, stating that “the Board performed a thorough analysis of the factual evidence and considered a variety of statements by experts for both parties and the inventors, past failures and successes in the field, evidence of simultaneous invention, and the extent to which the art provided instructions for applying the CRISPR-Cas9 technology in a new environment.” The University of California has not indicated whether it will appeal the ruling to the Supreme Court. “We are evaluating further litigation options,” said UC general counsel Charles Robinson in a statement.