The International Union of Immunological Societies (IUIS) is an umbrella organization for many of the regional and national societies of immunology throughout the world. As articulated in its Constitution, the objectives of IUIS are: - to organize international co-operation in immunology and to promote communication between the various branches of immunology and allied subjects - to encourage within each scientifically independent territory co-operation between the Societies that represent the interests of immunology - to contribute to the advancement of immunology in all its aspects. There are currently 88 Member Societies of IUIS, many of which belong to one of 4 Regional Federations encompassing Europe, Latin America, Africa and Asia-Oceania or are direct members such as US and Canada. That represents more than 60 000 immunologists all over the world. Links with other international scientific bodies are promoted through the International Affiliate Members of IUIS, membership of the International Council for Science (ICS) and formal liaison with the World Health Organization (WHO).