A lawyer for a man who developed cancer after decades of using Monsanto’s Roundup said Wednesday that the company “influenced and manipulated” science surrounding the weedkiller and its active ingredient, through its relationships with regulatory officials and by ghost-writing scientific studies.

Aimee Wagstaff of Wagstaff Andrus focused on Monsanto’s ghost-writing efforts and “cozy relationship” with some EPA officials during opening arguments on behalf of Edwin Hardeman, a Northern California man who developed non-Hodgkin lymphoma. Wagstaff’s remarks came on the first day of the damages and liability phase of the first bellwether case to go to trial in the massive Roundup multidistrict litigation. A San Francisco jury on Tuesday found that Hardeman had proven that Roundup more likely than not was a substantial factor in his cancer.