Some advisory committees may have direct control over program administration. Each of the nineteen institutes within the National Institutes of Health(NIH) has an advisory council whose members must be leaders in science, medicine, and public affairs, including some who are specialists in the field covered by a particular institute (e.g., cancer, aging, or allergy and infectious diseases). Research grants to medical schools, universities, and others, which total more than $20 billion annually, can be made only after review and approval by each institute’s advisory council. This is intended to ensure that grants meet both scientific norms and public-policy criteria.