Most developed countries of the world have programs of cancer research. The federal government's National Cancer Institute and a group of private organizations have focused on such research in this country. Among the private groups are the American Cancer Society, the Damon Runyon Walter Winchell Cancer Fund, and the Leukemia Society of America. On the international level, researchers at the World Health Organization and the International Agency for Research on Cancer cooperate on cancer studies and public education about cancer. Knowledge of the causes and control of cancer has increased dramatically in recent years.