The purview of the federal antitrust statutes is limited to conduct that concerns trade or commerce. The relevant inquiry typically focuses on whether the conduct is "in" or "affects" interstate commerce. The required effect on commerce varies depending on which antitrust statute is implicated. This practice note provides guidance regarding the effect on commerce required to establish jurisdiction under the relevant federal statutes, including the Sherman Act, the Clayton Act, the Robinson-Patman Act, and the Federal Trade Commission (FTC) Act. It also addresses commerce issues implicated by the Foreign Trade Antitrust Improvements Act (FTAIA) and principles of international comity. For more background on the U.S. antitrust laws generally, including why effect on commerce is a relevant consideration, see the practice notes Antitrust Law Fundamentals and Sherman Act Section 1 Fundamentals. For more background on the Robinson-Patman Act, see the practice note Robinson-Patman Act Section ...