Allergy and Infectious Diseases, National Institute of (NIAID): One of the U.S. National Institutes of Health (NIH), the mission of the NIAID is "to support and conduct research and research training (that) strives to understand, treat, and ultimately prevent the myriad infectious, immunologic, and allergic diseases that threaten millions of human lives." Immunology figures into this statement presumably because it is the common foundation for infectious diseases and allergy.