PEOPLE magazine’s Most Beautiful person of the year, Christina Applegate, is using her beauty for a good cause. The breast cancer survivor is the 2009 Ambassador for Lee National Denim Day to support the fight against the disease — and PEOPLE.com has an exclusive first look at her stunning campaign shot. As part of charity effort, which is one of the country’s largest single-day fundraisers for breast cancer, the Samantha Who? star is asking companies to get casual for the cause and encourage their employees to wear jeans to work on Friday, October 2 — in exchange for $5 donations to support the charity. “Lee National Denim Day is such an effective grassroots campaign and its importance has become even more real to me in this past year,” Christina says. “By joining together on October 2, we can raise millions to support breast cancer research. It’s so simple and so powerful. I truly believe that events like this help save lives.” Proceeds from the program, which has already raised over 75 million dollars since its inception in 1996, will benefit Women’s Cancer Programs of the Entertainment Industry Foundation. Log on now to denimday.com to learn more about Lee National Denim Day and register your own group, or just support any existing team. Then get set to slip into your favorite jeans in the name of a good cause on October 2.