Communication between the outside and inside of cells relies on protein molecules (such as integrins) at the cell surface, which interact with the external environment and send signals to other molecules inside the cell. These molecules interact to form complex signaling cascades to effect appropriate cell responses. Protein tyrosine phosphatases (PTPs) are a family of proteins that play a critical role in cell signaling processes. Shirley Chen is investigating the function of PTPalpha, an important player in integrin signaling. This signaling pathway regulates cell growth, migration, and survival, and has been implicated in cancer development and progression. By studying the activity of PTPalpha-deficient cells in comparison to normal cells, she will learn more about the role of this protein in the integrin signaling cascade. Since integrin signaling governs several aspects of how a cell responds to the environment, her study of this process will help reveal why certain cells, such as cancer cells, behave abnormally. In the long term, her research could contribute to understanding the onset and course of diseases such as cancer and diabetes, and may potentially lead to PTPalpha-based therapeutics for these diseases.