He completed his PhD in Trinity College Dublin in 2000, before undertaking postdoctoral fellowships at the European Institute of Oncology, Milan and the Centre of Epigenetics in Copenhagen. In 2008, he returned to Dublin and today is an Associate Professor in the School of Genetics and Microbiology. His research focuses on the field of epigenetics and its relevance to stem cells and cancer. His lab regularly publishes their work in high-profile Nature and Cell press journals. He has also translated his lab's basic research findings, including developing a new diagnostic tool called OncoMasTR, designed to aid oncologists determine the best treatment options for breast cancer patients. In 2017, he was awarded €2.5M funding from Science Foundation Ireland, The Worldwide Cancer Research Fund, and the Health Research Board to continue to study the genetics and epigenetics of several types of cancer.