NIH Scientific Interest Groups are assemblies of scientists with common research interests. These groups sponsor symposia, poster sessions and lectures; offer mentoring and career guidance for junior scientists; help researchers share the latest techniques and information; act as informal advisors to the Deputy Director of Intramural Research (DDIR); provide advice for the annual NIH Research Festival; and serve as hosts for the Wednesday Afternoon Lecture Series. Many of these groups are cosponsored by neighboring academic and government institutions and welcome interested non-NIH scientists.