he ability to use mammalian and nonmammalian organisms to create experimental models that mimic human cancer facilitates both basic science investigation and the testing of promising agents for cancer prevention and treatment. These models allow researchers to study and understand cancer in ways impossible just a few years ago.

In December 1996 , NCI Director Dr. Richard Klausner convened a Working Group to help NCI plan how to optimize the development and use of model systems. The mission of the Preclinical Models for Human Cancers Working Group is to identify broad scientific opportunities that would enable NCI to:

• Apply knowledge of nonmammalian genetic systems to the study of human cancer
• Create models of tumor development in mice based on knowledge of human cancer genes and use these models to study the biology of tumor development
• Use the mouse models of tumor development to study methods of cancer intervention
• Develop the infrastructures needed to make these models available to the research community