Neuralink is a startup that Musk is interested in investing in.

According to four sources, the billionaire approached the CEO of Synchron about taking a stake in the company.

The report said it was unclear if Thomas Oxley would accept an offer.

Neuralink is trying to catch up with Synchron, which started a human trial of its technology in July. The device was implanted into the first patient. The first patient has a disease called amyotrophic lateral sclerosis, also known as Lou Gehrig's disease. The goal is for the device to translate the patient's thoughts into action by sending them commands to a computer.

There is a human trial. Four patients with no negative side effects were the first to be conducted in Australia.

Neuralink hasn't begun human trials. It is not known what stage the company is at in applying to the FDA to begin human trials.

Both startup want to create technology that can translate thoughts into actions for people who have been affected by a disease.

Synchron and Neuralink did not reply immediately.

According to former and current employees, Musk reached out to Oxley after he made his displeasure known. Fortune has reported tension within Neuralink before.

The former president of Neuralink is an investor in Synchron.

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