The billionaire has reportedly approached the CEO of Synchron, which is developing brain implants, about potentially taking a stake, according to Reuters, citing four sources familiar with the matter.

It’s unclear whether Thomas Oxley, Synchron’s CEO, will accept an offer, the report said.  

Neuralink is trying to catch-up with Synchron, which in July began its first U.S. human trial of its technology. The trial involved implanting its device into the first of six patients. The first patient has ALS, a progressive neurodegenerative disease that affects nerve cells in the brain and spinal cord. The goal is for the device to translate the patient’s thoughts into action—including browsing online and communicating via email—through commands that are sent to a computer. 

Synchron’s human trial is its second. The first was conducted in Australia with four patients who had no negative side-effects and were able to communicate and make purchases online, Bloomberg reported.

Neuralink, founded in 2016, has yet to begin human trials. And it’s unclear what stage, if any, the company is at in applying with the U.S. Food and Drug Administration for approval to begin human trials, the report said. 

Both startups want to create technology that, in layman’s terms, translates thoughts into actions for people whose ability to move or speak have been affected. 

Synchron and Neuralink did not immediately respond to Fortune’s request for comment. 

Former and current employees told Reuters that Musk was frustrated by Neuralink’s slow progress on its technology, and his reaching out to Oxley came after he made his frustration known. Tension within Neuralink is not new, as Fortune has previously reported. 

Neuralink’s former president Max Hodak left the company after serving as its leader since its founding and is now an investor in Synchron.