On November 27, 2019, the Antitrust Division of the U.S. Department of Justice (“Division”) announced that it had completed its investigation into the standard-setting activities of GSM Association. The Division ended the investigation by issuing a business review letter, which provided guidance on procedural protections standard-setting organizations might use to protect their deliberations from anticompetitive influence. The letter is noteworthy because (i) it provides insight into the Division’s current thinking about standard-setting activities and (ii) it represents an unusual use of a business review letter, and suggests that business review letters could be part of a discussion about how to close future investigations.