The U.S. Patent and Trademark Office agreed Monday to decide whether a UC Berkeley research team will be awarded the rights to the groundbreaking CRISPR-Cas9 technology, which could be worth billions of dollars and serve as the foundation for the burgeoning field of gene editing.

The UC Berkeley team, led by campus chemistry professor Jennifer Doudna, claims they invented the CRISPR-Cas9 technique, which uses the Cas9 protein as molecular “scissors” that precisely cut and replace targeted DNA strands. The technology is particularly useful in the context of repairing genetic mutations that cause hereditary diseases, such as sickle cell disease.

MIT biomedical engineering professor Feng Zhang also claims to have invented the technology, which Science magazine named the 2015 Breakthrough of the Year. At the same time, however, Doudna and her colleague received the $3 million Breakthrough Prize — given out annually by Silicon Valley entrepreneurs — for her work with the same technology, while Zhang was not awarded.

Earlier this week, an administrative patent judge declared an “interference” between the competing claims, meaning the Patent Office will now have to determine which party will be granted the enormously lucrative rights to CRISPR-Cas9.

“The U.S. Patent and Trademark Office has declared that a dozen of Feng Zhang’s patents appear to cover the same technology claimed in Jennifer Doudna’s pending patent application,” said Jacob Sherkow, an associate professor at New York Law School. “Because it appears that Zhang’s applications were filed after Doudna’s, this suggests that Zhang’s patents are ‘interfering’ with Doudna’s ability to have her patent application granted.”

Although patents are granted on a “first to file” basis as of 2013, the CRISPR dispute will be settled under the original “first to invent” standard, because both patents were filed in 2012 before the new rule was put into effect.

Thus, even though Doudna filed her application first, the ultimate owner of the CRISPR intellectual property is still undetermined, with both sides scrambling to prove that they made the discovery before the other.

The Patent Office guidelines specify that a decision must be reached within 24 months after an interference is declared, according to Greg Reilly, an associate professor at the California Western School of Law. Reilly noted, however, that appeals are likely to lengthen this process.

“Because this case is subject to so much publicity, the Patent Office will want to act as promptly as possible,” Reilly said in an email. “On the other hand, because there is so much at stake, the losing party will do everything they can to prolong it through appeals.”

In the meantime, Doudna, Zhang and the entire scientific community are left awaiting the decision that promises to shape the future of gene editing.

Logan Goldberg is the lead research and ideas reporter. Contact him at [email protected].