All cells must replicate their genetic material (DNA), which is organized into chromosomes. A fundamental component of many normal and disease-related processes is the replication of DNA, whose control occurs at the level of initiation. Dr. Zannis-Hadjopoulos’ laboratory has been studying the regulation of initiation of human DNA replication, using cell cultures. They have been concentrating on studying the DNA sites where replication starts (replication origins) and the factors that are involved, in order to understand how the initiation of replication is regulated. Dr. Zannis-Hadjopoulos’ team previously identified Ku as a protein involved in the initiation of DNA replication. As its expression is deregulated in breast cancer and Ku plays key roles in cell growth and death, they propose to explore its role in breast tumorigenesis and tumor progression, using human cell culture, in order to identify novel therapeutic strategies.