The National Cancer Institute (NCI) is a part of the U.S. Department of Health and Human Services. It is the federal government's principal agency for cancer research and training. NCI's mission is to conduct and support research, provide information about cancer, and promote cancer prevention and treatment strategies. NCI also plays a key role in funding cancer research projects and clinical trials. It collaborates with various institutions, including universities and hospitals, to advance the understanding of cancer. Through its efforts, NCI aims to improve patient outcomes and reduce the burden of cancer on society.