Clinical trials enable scientific discoveries to advance patient care, and they also inform and guide subsequent research. The National Cancer Institute (NCI) supports the largest . network of clinical trials of any type, of which the largest component is the Clinical Trials Cooperative Group Program (informally known as the Cooperative Group Program). It currently comprises 10 Groups that involve more than 3,100 institutions and 14,000 investigators who enroll more than 25,000 patients in clinical trials each year. Since its inception in the 1950s, the Cooperative Group Program has been instrumental in establishing the standards for cancer patient care and clinical research methods. Research performed by the Cooperative Groups has significantly.