The patent system focuses on the actions of two players: the patentee and its competitor. It assumes that the competitor will represent the interests of the end user. But, end users are increasingly becoming significant players in the patent system, with their interests sometimes diverging from those of competitors. Attention has recently turned to Patent Assertion Entities (“PAEs”)—also known as patent trolls—who are suing vast numbers of customers using patented technologies in their everyday businesses. Yet, end users were also principal players in some of the main recent patent cases before the U.S. Supreme Court. In Bowman v. Monsanto Co., Monsanto sued farmers for re-using its patented self-replicating seeds. In Association for Molecular Pathology v. Myriad Genetics, patients and physicians sued to invalidate breast cancer gene patents. And, patients and drug stores repeatedly challenge pay-for-delay agreements between patentees and competitors, claiming they undermine patients’ interests in access to generic drugs.