Let us revel in the irony: The US Patent Office will now resolve a dispute over one of the hottest biotech breakthrough of the decade, the genome-editing technology Crispr/Cas9, through an arcane proceeding that technically should no longer exist. Because the disputed patents date back to just before a new law took effect in 2013, the patent office will work out who gets credit for inventing Crispr via a so-called interference proceeding—probably one of the last such proceedings ever.

Even outdated patent laws like to go out with a bang.

And what a bang it could be, given the billion-dollar implications. Crispr/Cas9 allows scientists to precisely manipulate genes in any living thing, including humans. If the implications bear out, that could mean cures for diseases, famine- and climate-proof food crops, and all sorts of other science-fiction outcomes. UC Berkeley and the Broad Institute in Cambridge, Massachusetts both have researchers with claim to the creation of the world-changing invention.

The money is getting as real as the lab results. The gene-editing company Editas, which licenses the Broad’s patent, filed for a $100 million IPO on Monday. If the interference proceeding negates the Broad’s patent, that could spell the end of Editas (and all that capital!) while clearing the way for several other companies that have licensed the competing, Berkeley-originated patent. A lot is at stake.

Interference proceedings are rare, says Jacob Sherkow, a professor at New York Law School, who first pointed out the development in a blog post. But when they happen, they’re high profile. “Because of how much interference proceedings cost,” he says, “inventors tend not to fight about it unless it’s really really worth it.”

An appeals board still needs to formally initiate the interference proceeding, but in December a patent examiner recommended they do so, and the board pretty much always follows an examiner’s recommendations. It’ll look a lot like court, with a three-judge panel and oral arguments. Star scientists on both sides, Jennifer Dounda of Berkeley and Feng Zhang of the Broad, could testify. “We’re obviously looking for this getting resolved, but it’s just another step in the process,” says Broad spokesperson Paul Goldsmith. “We have no idea about the timeline,” he adds.

Representatives from UC Berkeley declined to comment, but the interference proceeding clearly works in the university’s favor. Berkeley had filed the earliest patent on Doudna’s Crispr/Cas9 work on May 25, 2012—but the patent office initially awarded the patent to the Broad, which had paid to fast-track its later application. The provisional patents on both sides both made it in before the March 16, 2013 date when a new patent law took effect.

For decades, the US patent system was unusual in that it decided patents on a first-to-invent basis. Pinning down any complex invention to a single date can be difficult. Case in point: Editas's own IPO filing acknowledges patent disputes, and not just with Berkeley, as one of the risks of its business. Interference proceedings were supposed sort these out. But with the 2013 law, the US patent system switched over to a first-to-file system, so such proceedings would no longer be necessary. But because the provisional patents was filed just before that law went into effect, it triggered the now outdated first-to-invent criteria. This April, Berkeley filed for an interference proceeding that’s now been granted. The arguments will rest on whether getting Crispr to work in a test tube counts as the invention, which Doudna's patents show first, or getting it to work in live cells is the real which, which Zhang's patents show first.

Outside of the legal system, both Berkeley’s Doudna and the Broad’s Zhang have been the subject of glowing profiles about their Crispr research (including in WIRED). The stories vary dramatically is how much they focus on Doudna versus Zhang, whichjournalists have intimated had to do with lack of access to the researchers. The two sides are fighting a public relations war as much as legal one. Doudna and Zhang have also planted their stake in Crispr/Cas9 in very different ways: Doudna has become a voice for ethical questions about Crispr and Zhang has continued to publish more finely-tuned technical tools.

In the world of patent law, though, the PR battle is just distraction. “I really struggle to think a set of [Patent Trial and Appeals Board] judges, who are famously sticklers for procedure, are going to care about any of that stuff,” says Sherkow. The world will soon get to see that in action.