David Boies, Boies, Schiller & Flexner Jason Doiy / The Recorder

SAN FRANCISCO — As lab test startup Theranos Inc.’s woes multiply with a wave of class action lawsuits, board member David Boies is showing no sign of reducing his firm’s role as chief defender of the company.

In filings in federal court here Wednesday, three Washington-based attorneys for Boies, Schiller & Flexner entered appearances on behalf of Theranos in a proposed class action suit that alleges the company misled consumers about the reliability of its blood testing technology.

Earlier this month, Los Angeles-based Sean Eskovitz—a Boies Schiller alum—came to the company’s aid as local counsel in the case. (Theranos’ general counsel, Heather King, is also a Boies Schiller alum.)

It’s the continuation of a long relationship between the now embattled Silicon Valley company and the litigation powerhouse. Boies himself, chairman and founder of the firm, went to battle for Theranos in a bitter patent dispute against a father-son inventor team that ended with a settlement in 2014. In 2015, Boies joined the company’s board of directors and then represented them in connection with claims the company’s technology was flawed.

Since then, observers like UC-Berkeley law professor Steven Davidoff Solomon have questioned Boies’ dual roles: representing the interests of Theranos’ private investors as a board member, and defending the company as its lawyer.

With Thursday’s appearances in the consumer class actions, “he’s just doubling down on the conflict” Solomon said. If the company’s regulatory and legal problems ultimately evaporate, that may not pose an actual problem, Solomon added. But if things go south, that could put Boies in a “sticky situation,” he said.

Boies could not be reached for comment.

In an interview with The New York Times in April, Boies said that Theranos CEO Elizabeth Holmes continues to have the board’s full backing. At the same time, he said another unnamed law firm was responding to queries from the U.S. Attorney’s Office in San Francisco and the Securities and Exchange Commission, and conducting an independent investigation into whether Theranos made proper disclosures to investors.

The Boies Schiller attorneys who appeared Thursday in the class action suit are Michael Brille, Amy Mauser and Evan North. Theranos has not named counsel for at least four other pending suits that involve similar claims.

The class action blitz comes after Theranos in March voided two years’ worth of blood test results following warnings from federal regulators about the adequacy of the labs. The Wall Street Journal has also reported that Holmes and a former executive who has now departed have also been threatened by regulators with a two-year ban from running any lab.

Contact the reporter at bhancock@alm.com.