Hillary Clinton launched the latest salvo in the war between White House contenders and Turing Pharmaceuticals CEO Martin Shkreli on Monday.

In a letter to Federal Trade Commission Chairwoman Edith Ramirez, Clinton urged the agency to probe whether Turing’s “restricted distribution program” for the drug Daraprim amounts to anti-competitive behavior.

Shkreli has become a target for presidential candidates Clinton, Bernie Sanders and Donald Trump after Turing jacked up the price of the drug to $750 a dose from $13.50. Daraprim is used to treat life-threatening infectious diseases.

Also read:Bernie Sanders doesn’t need Martin Shkreli’s stinkin’ biotech money.

Clinton made the Turing request to the FTC at the same time she asked for the agency to study dramatic drug-price increases that cause “real barriers for consumers,” while there is a long lag in approval of potential competitors.

In a separate letter to U.S. Food and Drug Administration Acting Commissioner Stephen Ostroff, Clinton said Turing still hasn’t “meaningfully lowered the price” of Daraprim. She said the FDA should speed up any pending reviews of generic alternatives to the drug “and make these drugs available to U.S. patients as quickly as possible consistent with safety and efficiency.”

Asked for comment about Clinton’s letters, a Turing spokesman pointed to an Oct. 13 release from the company that says its goal is to “ensure that every patient who needs Daraprim has ready and affordable access to it.”

Shkreli has addressed both Clinton and Sanders directly on his Twitter feed. He has also been the subject of Donald Trump’s wrath.