This article focuses primarily on recent changes to irreparable harm standards, how those changes have altered the patent litigation landscape. Patent litigation is the process through which one party sues another for making allegedly unlawful claims upon their patented invention.This chapter explores the theory behind injunctive relief in patent cases, surveys the availability of this remedy in major patent systems, We maintain the public record of court proceedings, ensure access to the Court, and provide administrative support to all of the Court's judicial officers. Mayer Brown's Patent Litigation practice has the breadth and depth of experience to assist clients in all facets of protecting their business. A federal appeals court confirmed a substantial question of patent invalidity is required to defeat a preliminary injunction against infringement. The court looked to the guidance in eBay that any injunctive relief should be consistent with the "traditional principles of equity. , Nuclear-Chicago Corp. v. Donoghue is also the founder and principle author of the Chicago IP Litigation and Retail Patent Litigation blogs. Original language, English (US).