After months of visible discomfort, Walgreens Co. officially ended its partnership with blood testing company Theranos.

In a news release issued late Sunday, Walgreens announced the company had informed Theranos that it was calling off its nearly three-year-long relationship. Walgreens will close all 40 Theranos Wellness Centers in its drug stores “effective immediately.” The announcement comes after Theranos voided or corrected tens of thousands of tests and faces possible federal sanctions for repeated failures at one of its labs.

“In light of the voiding of a number of test results, and as the Centers for Medicare and Medicaid Services (CMS) has rejected Theranos’ plan of correction and considers sanctions, we have carefully considered our relationship with Theranos and believe it is in our customers’ best interests to terminate our partnership,” Brad Fluegel, Walgreens' senior vice president, said in the news release.

The Wall Street Journal reports that federal regulators may make a decision on sanctions within the next two weeks. Those sanctions could include revoking the company’s license to perform medical tests and/or banning Theranos CEO and founder Elizabeth Holmes from the blood testing industry for at least two years.

The events are a sharp turn from the promising start of the Silicon Valley firm, which in 2014 garnered enough buzz to earn a $9 billion valuation from investors. The company made waves touting that its blood testing devices could perform more than 200 tests with just a few drops of blood. Though Theranos has yet to publish data on its blood testing devices, the $50 million deal with Walgreens, the nation’s largest drug store chain, provided some credibility to the claims.

Nevertheless, Theranos has been dogged by questions about the accuracy and quality of its blood testing technology since last fall. Inspections by the CMS uncovered a series of violations at its labs, including one that posed “immediate jeopardy to patient health and safety.” In an attempt to appease the CMS, Theranos voided or corrected tens of thousands of 2014 and 2015 test results last month. Theranos is also facing three civil lawsuits over its bunk blood tests, and its valuation dropped to 800 million.

All the while, Walgreens became increasingly uncomfortable with its tie to Theranos and planned to get out of the deal. It allegedly held off until now out of fear that Theranos would sue, according to the WSJ. But, as the journal also reports, Walgreens’ executives have recently become increasingly convinced that Theranos will get slapped with painful sanctions, which would make it much easier for the drug store giant to justify the split.

In a statement to the WSJ, Theranos spokesperson Brooke Buchanan said: “We are disappointed that Walgreens has chosen to terminate our relationship and remain fully committed to our mission to provide patients access to affordable health information and look forward to continuing to serve customers in Arizona and California through our retail locations.”

Theranos is reportedly looking for other commercial partners and has made plans to expand its testing in Arizona. In August, Holmes is scheduled to reveal data on the company’s proprietary blood technology and field questions about its tests at an annual conference of the American Association for Clinical Chemistry, which will be held in Philadelphia.