The plaintiff in this case sued Monsanto, asserting claims arising from his exposure to the pesticide Roundup. After the district court held that his claims are expressly preempted by the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), 7 U.S.C. § 136 et seq. , the plaintiff appealed the court’s ruling as to his failure-to-warn claim. Public Citizen filed an amicus brief in support of Mr. Carson in the court of appeals, explaining that FIFRA neither expressly nor impliedly preempts his claim. In a unanimous opinion issued in July 2022, the court of appeals agreed, rejecting Monsanto’s preemption argument. Monsanto filed a petition for rehearing, after which the panel issued a new opinion reaching the same result.