Singer Aaron Carter signed autographs for some of the hundreds of patients and their families at the 16th annual "Celebrate Life with Hope," part of National Cancer Survivors' Day, on Sunday, June 10, 2007 at Paramount Studios. The celebration is the largest event for pediatric cancer survivors in the Western United States and provides patients, caregivers and former patients from the Childrens Center for Cancer and Blood Diseases at Childrens Hospital Los Angeles a chance to reunite with each other.