When trying to understand and eventually cure cancer, it is important to identify the cellular components that either protect cells from cancer or contribute to the cancer state. While most cancer-related genes fall into either of these two opposite categories, two of our cellular proteins, Skp2 and Cks1, have been implicated in both. The aim of this research program is to understand how they function in these apparently opposite roles in the cell. We will use a simple model organism, the fruit fly, to answer these questions. Our findings will lead to a better understanding of cancer and may lead to improved treatments in the long term.