Drugstore giant Walgreen Co. sued former laboratory-testing partner Theranos Inc. in a federal court in Delaware, alleging it breached a contract between the two companies. 
 
 The Walgreens Boots Alliance Inc. unit is seeking $140 million in damages, equal to the amount it invested in Theranos, according to people familiar with the matter. 
 
 The... 

 Embattled startup Theranos Inc. was sued by Walgreens Boots Alliance Inc. in connection with claims it violated an agreement tied to a scandal over faulty blood-testing claims. 
 
 Deerfield, Illinois-based Walgreens, which joined with Theranos to provide testing at some of its retail stores, filed a sealed lawsuit against its former partner on Tuesday in federal court in Delaware. The suit seeks $140 million in damages, the Wall Street Journal reported, citing court records that couldn’t be confirmed in the public docket. 
 
 Walgreens terminated its relationship with Theranos and closed 40 Arizona sites in June after questions arose about whether the Palo Alto, California-based company misled consumers and investors about the validity of its testing capabilities. 
 
 The most important business stories of the day. Get Bloomberg's daily newsletter. “Over the years, Walgreens consistently failed to meet its commitments to Theranos,” the startup said in a statement on its website. “Through its mishandling of our partnership and now this lawsuit, Walgreens has caused Theranos and its investors significant harm. We will respond vigorously to Walgreens’ unfounded allegations, and will seek to hold Walgreens responsible for the damage it has caused to Theranos and its investors.” 
 
 Michael Polzin, a spokesman for Walgreens, declined to comment on the case. 
 
 Walgreens joins testing patients who’ve already sued Theranos, claiming faulty blood-test results led to heart attacks and other issues. It’s also facing fraud claims in state court in Delaware from one of its investors. 
 
 Voided Results 
 
 Theranos’s reputation suffered a hit after it issued tens of thousands of corrected or voided results to former patients. It’s been investigated by federal prosecutors, securities regulators and federal and state health officials. 
 
 U.S. District Judge Sue Robinson in Wilmington, Delaware, agreed to seal the suit for seven days so Theranos officials can decide whether it contains any proprietary information, according to a public court filing. 
 
 Walgreens claims Theranos misled it about the state of its technology when the two firms entered into their agreement, the Journal reported, citing unidentified people familiar with the suit. 
 
 The case is Walgreens Co. v. Theranos Inc., No. 16-cv-1040, U.S. District Court for the District of Delaware (Wilmington). 

 Walgreens has filed suit against Theranos in Delaware district court, asking for $140 million and alleging a breach of contract. 
 
 Walgreens successfully moved to seal the complaint, citing the non-disclosure agreement, so the details of the alleged contractual breach are still unknown. A Walgreens spokesperson confirmed that the company had filed the lawsuit, but declined to add further comment. 
 
 Theranos, once a Silicon Valley darling promising accurate blood tests using only a pinprick, recently closed its labs and fired 340 employees after a series of articles exposed that its technology did not work and was putting patients at risk. The startup and its founder, Elizabeth Holmes, have been hit by a growing number of lawsuits in recent months, including at least eight from patients claiming that its technology caused heart attacks or other health problems. It has also been sued by one of its own investors for fraud. 
 
 Walgreens had been one of Theranos’ most high-profile partners, even opening 40 "Theranos Wellness Centers" in its Arizona locations and agreeing to partner before even testing the technology. The drugstore chain stopped expanding its Theranos centers last October and ended the partnership in June. The full complaint is sealed. 
 
 The lawsuit claims that Theranos misled Walgreens about its technology when the companies decided to partner and again during the period of growing doubt surrounding the start-up, a person familiar with the matter told The Wall Street Journal. 
 
 A spokesperson for Theranos said that the company was “disappointed” that Walgreens had decided to file the lawsuit. “Over the years, Walgreens [has] consistently failed to meet its commitments to Theranos,” the spokesperson wrote in an email to The Verge. “Through its mishandling of our partnership and now this lawsuit, Walgreens has caused Theranos and its investors significant harm. We will respond vigorously to Walgreens' unfounded allegations, and will seek to hold Walgreens responsible for the damage it has caused to Theranos and its investors.” 
 
 Read the full motion to seal below. 
 
 Correction: The reasons driving this breach of contract lawsuit are unclear. An earlier version incorrectly said that Walgreens claimed that Theranos’ actions violated non-disclosure and confidentiality agreements. 

 “We are disappointed that Walgreens filed this lawsuit. Over the years, Walgreens consistently failed to meet its commitments to Theranos. Through its mishandling of our partnership and now this lawsuit, Walgreens has caused Theranos and its investors significant harm. We will respond vigorously to Walgreens’ unfounded allegations, and will seek to hold Walgreens responsible for the damage it has caused to Theranos and its investors. 
 
 Several years ago, Theranos adapted its business plan to become a clinical lab, and gave up significant opportunities in order to formalize an exclusive relationship with Walgreens. As a small company, we relied on Walgreens’ promise to help us build a substantial commercial footprint. By failing to follow through on that promise and others, Walgreens breached our contract and inflicted damage on Theranos and its investors. Theranos has been considering affirmative litigation against Walgreens for some time. In light of today’s news, we will proceed aggressively to recoup the damage caused by Walgreens.”
– Theranos has yet another lawsuit on its hands. Walgreens wants $140 million in damages—reportedly the same amount it invested in Theranos—after it had to close the Theranos blood-testing centers at 40 of its stores, according to a breach of contract suit filed under seal on Tuesday because of a non-disclosure agreement, per the Verge. Walgreens blames Theranos for the failed deal, claiming it misled Walgreens about its pinprick technology even after it came under fire last year, reports the Wall Street Journal. Theranos CEO Elizabeth Holmes isn't taking the suit lightly. "We will respond vigorously to Walgreens' unfounded allegations, and will seek to hold Walgreens responsible for the damage it has caused to Theranos and its investors … through its mishandling of our partnership and now this lawsuit," she says in a statement. "Over the years, Walgreens consistently failed to meet its commitments." Theranos also faces lawsuits from patients who claim its technology caused health issues, including heart attacks, reports Bloomberg.