Dean Felsher is a professor of oncology and pathology, and the director of TRAM. His laboratory investigates how oncogenes initiate and sustain tumorigenesis. He has developed model systems whereby he can conditionally activate oncogenes in normal human and mouse cells in tissue culture or in specific tissues of transgenic mice. In particular using the tetracycline regulatory system, he has generated a conditional model system for MYC-induced tumors. He has shown that cancers caused by the conditional over-expression of the MYC proto-oncogene regress with its inactivation. Thus, even though cancer is a multi-step process, the inactivation of one oncogene can be sufficient to induce tumor regression. Now, he is using these model systems to address three questions:

1. How do oncogenes initiate tumorigenesis?
2. How does oncogene inactivation cause tumor regression?
3. How do tumors escape dependence on oncogenes?