on Thursday his support for 's new CEO – a relief for the company as it tries to rebound from a with the billionaire activist investor.
"I think he will do an excellent job and he has my full support," Icahn said in a on X, noting that he spoke with Thaysen.
Icahn, who continues to own a small stake in Illumina, launched a proxy battle over the company's decision to close its $7.1 billion acquisition of cancer test developer Grail in 2021 without approval from antitrust regulators in U.S. and European Union.
Icahn was a staunch critic of Illumina's former CEO Francis deSouza, who ultimately resigned after the proxy battle in May despite securing enough votes to stay.
"I'd find it comical, if it wasn't so reprehensible that ILMN's share price is down 63% due to CEO Francis deSouza making such an absurd and questionable purchase," Icahn said in a statement to CNBC in March.
Shares of Illumina are now down nearly 70% since closing the Grail deal in August 2021. The company's market value has fallen to roughly $25 billion from around $75 billion in August 2021.
Investors will be watching to see how Thaysen approaches the Grail business, and whether he can rebuild the market value the company lost.
Thaysen will step in as Illumina's CEO on Sept. 25 after nearly a decade at medical devices firm Technologies, where he ran its largest analytical-lab unit, and doubled the division's operating profit.
