As measured by assets or total giving, the Bill & Melinda Gates Foundation (Gates Foundation) is by far the largest U.S. foundation. As of October 1, 2008, the Gates Foundation had an asset trust endowment of $35.1 billion, and distributed more than $3 billion per year. The structure, approach, and agenda of the Foundation are heavily influenced by its founders, and there is no doubt that the direction of philanthropy in the international health arena has been, in turn, heavily influenced by the magnitude of the Foundations giving. One example of the degree of their influence is the field of malaria treatment and prevention. Global efforts to reduce and eradicate malaria have been catalyzed by and coalesced around the organizations and approaches developed or funded by the Foundation.