The National Institutes of Health (NIH), part of the Department of Health and Human services, is the U.S.’s primary biomedical research agency. Every year, the NIH grants tens of billions of dollars to hundreds of thousands of researchers studying the causes, diagnosis, prevention, and cure of human diseases, the processes of human growth and development, the biological effects of the environment, and the understanding of mental, addictive, and physical disorders. The NIH funds over 25% of all U.S. biomedical research and has contributed to countless breakthroughs and innovations over the last century. Through the Human Genome Project, completed in 2003, the NIH laid the foundation for personalized medicine.
You can read more about the NIH here: http://www.nih.gov/
The NIH is composed of 27 institutes and centers focused on different areas of disease or functions of the body. The largest of these specialized organizations is the National Cancer Institute (NCI), which is dedicated to cancer research, training scientists, and providing the public with up-to-date information about cancer.
You can read more about the NCI here: http://www.cancer.gov/
A new center within the NIH, the National Center for Advancing Translational Sciences (NCATS) was established in the FY2012 federal appropriations bill at the recommendation of the Institute of Medicine. The goal of NCATS is to look at new and innovative approaches to researching and treating disease. Most NCATS projects are done through the Clinical and Translational Science Awards (CTSAs), which support specialized research facilities and training. One ongoing NCATS project is the Discovering New Therapeutic Uses for Existing Therapies initiative, which partners NCATS with pharmaceutical companies to examine alternative uses for drugs.
You can read more about NCATS here: http://www.ncats.nih.gov/