Meister, who founded his firm in 2011 after serving as Icahn's lieutenant, did not immediately respond to a request for comment. Filings also showed that ValueAct Capital, run by Mason Morfit, owned 328,045 shares at the end of December. ValueAct had established its Illumina position in the third quarter of 2023 and cut its stake by 37% in the fourth quarter. The firm did not immediately respond to a request for comment. Since Icahn's board challenge early in 2023, the company announced the departure of Francis deSouza who had been CEO and its decision in December to divest cancer blood test maker Grail after regulatory objections. A day after Illumina said it will part with Grail, Icahn sent a letter to other Illumina shareholders saying that he plans to oust directors, laying the groundwork for a second board challenge. He has not offered details on his plans since then and did not respond to requests for comment on Wednesday.