The AIDS Clinical Trials Group (ACTG), the largest HIV clinical trials organization in the world, plays a major role in setting standards of care for HIV infection and opportunistic diseases related to HIV/AIDS in the United States and the developed world. The ACTG is composed of, and directed by, leading clinical scientists in HIV/AIDS therapeutic research. The ACTG is funded by the Department of Health and Human Services, National Institutes of Health through the National Institute of Allergy and Infectious Diseases.