If you’ve had a blood test conducted by Theranos in 2014 or 2015, perhaps at a Walgreens store or medical center, you should probably contact your doctor.

The Wall Street Journal reported Thursday that the company has “voided” those two years of results from its supposedly revolutionary Edison blood-testing machines and that it is issuing tens of thousands of corrected reports to doctors and patients. “That means some patients received erroneous results that might have thrown off health decisions made with their doctors,” the newspaper cautioned.

Geoffrey Baird, an associate professor in laboratory medicine at the University of Washington in Seattle, told the publication that he believes the recall is “unprecedented.”

Theranos, once a darling of Silicon Valley with a valuation estimated at $9 billion, has been under fire in recent months after troubling reports about how it runs its tests and the accuracy of the results. In March, a study published in the Journal of Clinical Investigation drew concern when it found that Theranos tests were substantially more likely to flag results as abnormally high or low compared with Quest Diagnostics and Laboratory Corporation of America Holdings, or LabCorp. Federal regulators have proposed sanctions against the company and its founder, Elizabeth Holmes.

Brooke Buchanan, a spokeswoman for Theranos, said she could not respond to questions about what consumers should do or expect, but she issued this statement about the report: “Excellence in quality and patient safety is our top priority and we’ve taken comprehensive corrective measures to address the issues [that the Centers for Medicare and Medicaid Services] raised in their observations.”

“As these matters are currently under review,” she said, “we have no further comment at this time.”

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