The Alliance for Clinical Trials in Oncology is a national clinical trials network sponsored by the National Cancer Institute (NCI) that consists of nearly 10,000 cancer specialists at hospitals, medical centers, and community clinics across the United States and Canada. The Alliance is dedicated to developing and conducting clinical trials with promising new cancer therapies, and utilizes the best science to develop optimal treatment and prevention strategies for cancer, as well as researching methods to alleviate side effects of cancer and cancer treatments. The Alliance is a member of the NCI National Clinical Trials Network (NCTN) and also serves as a research base for the NCI Community Research Oncology Program (NCORP). The Alliance seeks to reduce the impact of cancer on people by uniting a broad community of scientists and clinicians from many disciplines, committed to discovering, validating and disseminating effective strategies for the prevention and treatment of cancer. Our mission is three-fold: To conduct high quality multidisciplinary cancer control, prevention, and treatment trials that engage a comprehensive research network; To further our understanding of the biological basis of the cancer process and its treatment, from discovery, to validation, to clinical practice; and To provide a scientific and operational infrastructure for innovative clinical and translational research in the academic and community settings.