Mark Lang


Professional Profile

“An 18-year veteran specializing in litigating complex intellectual property cases.”
– Kansas City Business Journal

With a combination of patent prosecution and litigation experience, Mark crafts sound strategies for defending infringement matters—and is a primary force behind Erise’s four consecutive defense verdicts in the U.S. District Court for the Eastern District of Texas.

Science and Technology. Mark brings to his matters a solid understanding of both the science behind their innovations and the logistics of deploying it.

Before joining the firm, he prosecuted patent applications on behalf of the U.S. Department of Energy in fields such as biotechnology, chemistry, nanotechnology, battery components, and green energy technologies such as clean coal. This work also included reviewing and negotiating intellectual property terms used in financial awards issued by the Department.

Moreover, prior to attending law school, Mark served as a quality assurance technician for a Fortune 100 pharmaceutical and medical devices corporation.

Litigation. Clients also benefit from Mark’s well-rounded legal background. Out of law school, he served as a judicial law clerk in the Chancery Division of the Cook County Circuit Court, an experience that armed him with real-world knowledge of a court’s innerworkings and perspectives.

He then served as an associate with a general litigation firm in Chicago, where he focused on commercial litigation, including trade secrets and contract disputes. He credits this tenure with helping him focus on each case’s business realities.

Since joining Erise in 2013, Mark has built a track record of success in litigation venues across the country. Among his recent accomplishments:

  • Earned a defense verdict in the Eastern District of Texas on behalf of NetScout Systems. The plaintiff, a patent holding company, sought more than $62 million in damages.
  • Earned a defense verdict in the Eastern District of Texas on behalf of Sony in a case involving the PS4 console and best-selling video games. The plaintiff sought more than $100 million in damages. The verdict was affirmed by the Federal Circuit.
  • Obtained summary judgment in Delaware federal court on behalf of Ubisoft in a case centered on patents related to a virtual reality computer system. The summary judgment was later upheld by the U.S. Court of Appeals for the Federal Circuit.
  • Won a defense verdict in the Eastern District of Texas on behalf of Sandvine, a network monitoring company.
  • J.D., The John Marshall Law School, cum laude
  • B.A., Biology, University of Kansas
  • Illinois (inactive)
  • Kansas
  • U.S. District Courts for the Eastern District of Texas
  • U.S. District Courts for the Northern District of Illinois
  • U.S. Patent and Trademark Office
  • Trailblazer,  Intellectual Property Law, The National Law Journal, 2023