Renata Hesse, the co-head of the antitrust department at Sullivan & Cromwell, has no shortage of work these days. According to financial market data provider Refinitiv, the firm was top among legal advisors in terms of deals announced through the third quarter, with a total of $269 billion worldwide. With the U.S. antitrust authorities with whom Hesse interacts on merger clearance issues currently taking aggressive and novel stands on competition issues, she and her team sit at the busy intersection of deal-making, regulatory work and potential litigation. Case in point: she and her team led the consent discussions with the U.S. Federal Trade Commission on behalf of client Amgen in the leadup to a settlement allowing the biotechnology company to move forward with a $27.8 billion deal to acquire Horizon Therapeutics.

The Litigation Daily caught up with Hesse–who earlier in her career twice served as acting assistant attorney general in charge of the Justice Department’s Antitrust Division—to discuss the current antitrust climate. What follows has been edited for length and clarity.