Abstract
The United States National Cancer Institute (NCI) has been investigating Nature as a source of novel agents for the treatment of cancer for over 45 years, and has contributed to the development of many of the currently available anticancer drugs. The National Cooperative Drug Discovery Group (NCDDG) program was started in 1983 as mechanism to promote multidisciplinary, multi-institutional approaches to drug discovery, and has led to the development of a number of successful clinical agents. The program is reviewed in terms of achievements and challenges facing further research in the exploration of natural resources as a source of new drugs.