In an appeal that could have wide-ranging ramifications for thousands of Roundup lawsuits, lawyers on both sides of a $289 million verdict now on appeal filed supplemental briefs Tuesday addressing whether federal law preempted claims that Monsanto Co. failed to warn about its herbicide’s health risks.

The supplemental briefs, which also included an amicus brief, filed by California Attorney General Xavier Becerra, come in the appeal of a $289 million verdict in 2018 to plaintiff Dewayne Lee Johnson, who alleged Roundup caused his non-Hodgkin lymphoma. California’s First District Court of Appeal, which has indicated that it could set oral argument for March or April, asked both sides to file supplemental briefs responding to three questions that addressed whether the U.S. Supreme Court’s decisions on federal preemption, such as Wyeth v. Levine, applied to Roundup.