Steffen Johnson, the co-lead of Winston & Strawn’s nationwide appellate and critical motions practice, has joined Wilson Sonsini Goodrich & Rosati as a partner in Washington.

Johnson specializes in appellate and Supreme Court litigation and has briefed more than 80 cases before the high court. Earlier this year, he represented Teva Pharmaceuticals, Inc. in its case against Helsinn Healthcare S.A.

Johnson had a long tenure at Winston & Strawn, spending nearly 15 years at the firm.

After a clerkship in the U.S. Court of Appeals for the Eighth Circuit, Johnson joined Mayer Brown as an associate in its Supreme Court practice in 1996. In 2002, Johnson joined the U.S. Department of Justice as an attorney advisor for the Office of Legal Counsel in the George W. Bush administration. In 2005, Johnson joined Winston & Strawn and became a part of the firm’s appellate practice.

Over the years Johnson has represented a bevy of high-profile clients from Fortune 100 companies to public officials, unions and religious institutions. In 2016 Johnson was a part of an team that represented New England Patriots quarterback Tom Brady in his “Deflategate” suspension appeal against the National Football League.

Johnson did not immediately return request for comment.