After Elon Musk accused Shark Tank star Mark Cuban of lying about a workplace policy, their feud took a new turn.

The CEO of Tesla engaged in a discussion over Harvard University’s Diversity, Equity, and Inclusion (DEI) policy on X, the former Twitter, according to The Sun.

Bill Ackman, the billionaire hedge fund manager, tweeted extensively earlier this month about Claudine Gay resigning as president of the institution due to allegations of plagiarism and antisemitism on campus.

“DEI is just another word for racism,” Musk said as he reposted the piece. Whoever uses it should be ashamed.”

In a series of tweets about the significance of DEI programmes, Cuban—who recently sold a majority stake in the Dallas Mavericks but retains operational control over the team—challenged Musk’s assertions.

“Good businesses look where others don’t, to find the employees that will put your business in the best possible position to succeed,” Cuban wrote.

“By extending our hiring search to include them, we can find people that are more qualified. The loss of DEI-Phobic companies is my gain.”

Musk appeared to mock Cuban when he asked, “Cool, so when should we expect to see a short white/Asian women on the Mavs?”