Financier Carl Icahn’s campaign to replace three of Illumina’s board nominees — CEO Francis deSouza, current chair John W. Thompson, and physician Robert S. Epstein — earned a stern rebuke from the DNA-sequencing company’s board of directors in a letter to shareholders released today.

“The Board does not endorse Carl Icahn or his unqualified nominees and believes the election of any such nominees would detract from Illumina's long-term strategy,” the letter stated.

“Illumina's Board is led by an independent chair, John W. Thompson, and all nine members are independent with the exception of the Chief Executive Officer. Members of the Board bring the highest personal character, integrity, and ethical standards, and reflect a range of professional backgrounds and skills relevant to Illumina's business,” the letter said.

Icahn wants Illumina to heed U.S. and European regulators who have ordered the company to divest its Grail subsidiary, which is working to develop cancer tests. Icahn blames the current leadership for having wiped out $50 billion in shareholder value as the company’s stock has fallen 56% since its peak in 2002.

In case any shareholders who supported Icahn’s nominees want to change their mind, Illumina’s board wrote, “if you inadvertently voted using Icahn's gold proxy card, you may cancel that vote simply by voting again TODAY using the Company's WHITE proxy card. Only your latest-dated vote counts.”

Illumina will hold its annual meeting, at which a new board will be elected, on May 25.