My research career has been dedicated to investigating the impact of DNA damage on the structure of DNA, cell function and organism health. The DNA in each of our cells is damaged thousands of times per day by exposure to environmental factors, dietary components, chemotherapeutic agents and even endogenous by-products of normal metabolism. Studying patients with rare diseases caused by inherited defects in DNA repair provides important insight into the consequences of DNA damage. These patients have a dramatically increased risk of cancer and age prematurely. We engineered mouse models of these genome instability syndromes as a sensitive tool to test hypotheses about how DNA damage promotes cancer and aging.