The U.S. Federal Trade Commission (FTC) has restored a rule that requires prior authorization for any mergers that affect a market that was the subject of previous allegations of attempted anticompetitive behavior. The agency’s press release on the change seems to respond to the decision by Illumina Inc. to complete its acquisition of Grail Inc. and its multicancer screening test, as indicated by the statement that the policy would address the behavior of companies that see little risk to their long-term market strategies despite FTC opposition to an acquisition.