Following in the footsteps of Gwyneth Paltrow and Heidi Klum, Uma Thurman is lending her celebrity to Saks Fifth Avenue's annual Key to the Cure initiative. As this year's ambassador, Thurman models a charitable T-shirt, which was designed by Donna Karan, and will also appear in a nationwide public service announcement. She was inspired to join the campaign after attending last year's Susan G. Komen Race for the Cure, where she shot off the starting gun. "It was amazing to see so many women united in this effort," Thurman said. "When [Key to the Cure] was presented to me, I thought, 'This is something that matters to me.'" Karan couldn't agree more, adding that "It's not just about dressing women; it's about addressing the issues that are so important to all of us." The limited-edition tee ($35) will be available October 1st at Saks Fifth Avenue, Off Saks and saks.com.