Christopher J. Renk

I'll research this attorney before drafting.

Good sources. Let me verify the firm move timing, current firm, and case outcomes.

Christopher J. Renk — patent litigation practice summary

Focus areas. Renk is a first-chair IP trial lawyer whose docket has centered on athletic footwear and knit-textile manufacturing technology (Nike's Flyknit family of utility and design patents), along with design patents, mechanical and consumer products, and a broader mix his firm bios describe as computer software, consumer electronics, electrical controls, internet content delivery, medical and surgical devices, contact lenses, fuel injection systems, heat transfer, and textiles processing. He also handles trademark, trade dress, copyright, trade secret, and false advertising matters, and is a registered patent attorney (Reg. No. 33,761). He is not a Wi-Fi/standards or pharmaceutical specialist; his tracked patent work is consumer-product and mechanical/design-patent oriented.

Side preference. He works both sides, roughly evenly on the tracked docket (2 plaintiff-side, 2 defendant-side), which is consistent with his own reported statement that about 60% of his workload is defense-side. He is not an NPE/PAE plaintiff's lawyer: his patent work is largely for operating companies, dominated by long-running representation of Nike, Inc., as both plaintiff/patent owner and as accused infringer/patent owner in adversarial PTAB proceedings.

Firm context. Renk is a partner at Arnold & Porter Kaye Scholer LLP in Chicago. He spent most of his career at Banner & Witcoff, Ltd. in Chicago, joining as an associate in 1988 and rising to principal shareholder and past president of the firm, before moving with colleague Michael J. Harris to Arnold & Porter — a move reflected in PTAB filings: he was appointed Nike's lead counsel while at Banner & Witcoff (2017) and appears as Arnold & Porter lead counsel in updated notices by August 2020. The tracked case list tracks that chronology: the adidas and Puma matters are Banner & Witcoff-era; the Lululemon matters are Arnold & Porter-era.

Notable matters. He has been one of Nike's primary outside IP litigation counsel since the late 1990s, including a six-month in-house secondment at Nike in 1999.

• Nike, Inc. v. Lululemon USA Inc. (S.D.N.Y.) — lead counsel for Nike; a March 2025 jury found lululemon infringed claims of U.S. Patent 8,266,749 (Flyknit) and awarded $355,450, while rejecting infringement of a second patent (9,375,046). Reported post-trial rulings in March 2026 granted lululemon judgment as a matter of law that the '749 patent is invalid as obvious, vacating the verdict; lululemon had also filed IPRs against the asserted patents, with the PTAB invalidating one patent (9,730,484) in March 2025.
• Nike, Inc. v. Puma North America, Inc. (D. Mass.) — plaintiff's counsel in Nike's Flyknit suit against Puma; the court denied Puma's motion to dismiss in October 2018, holding the asserted patents patent-eligible and the willfulness allegations sufficient. A parallel Puma IPR was terminated on settlement in December 2019.
• Lyons v. Nike (D. Or.) — obtained summary judgment of noninfringement for Nike over Air Jordan XXI/XXII cushioning inserts in 2012 (reconsideration denied 2013).
• Also represented Nike in obtaining preliminary injunctive/design-patent relief against imported infringing footwear (Nike v. Fujian Bestwinn (China) Industry Co., D. Nev.).
• Trademark/ITC work includes representation of Converse in a large ITC trademark matter.

PTAB/IPR experience. He appears regularly in AIA proceedings, primarily as Patent Owner's lead counsel for Nike. Reported results include a sweep in which the PTAB denied institution on all eight Skechers IPR petitions against Nike Free/FLYKNIT design patents (2016), and unanimous Board wins for Nike against adidas in the Flyknit IPRs (IPR2016-00921/-00922, including a post-SAS remand and supplemental briefing) and against adidas in IPR2013-00067. He also served as Nike's lead counsel in the Lululemon IPRs.

Bar/education. J.D., University of Minnesota (1988); B.S., Iowa State University; admitted in Illinois (1988), Minnesota, and the District of Columbia; admitted to the U.S. Supreme Court, the Federal Circuit, and the Fourth, Fifth, Sixth, and Seventh Circuits. He has taught patent trial practice and patent litigation as an adjunct at Georgetown University Law Center and at Northwestern University School of Law.

Caveats: The March 2026 JMOL ruling in the Lululemon case is drawn from secondary trade reporting (IP Law Daily/VitalLaw) rather than a reviewed opinion text, and the precise effective date of his move from Banner & Witcoff to Arnold & Porter is only documented as "recently" in an August 2020 PTAB filing.