Our broad long-term goal is to understand how mammalian cells maintain ordered control of DNA replication during normal passage through an unperturbed cell cycle, and in response to genotoxins (DNA-damaging agents). DNA synthesis is a fundamental process for normal growth and development and accurate replication of DNA is crucial for maintenance of genomic stability. Many cancers display defects in regulation of DNA synthesis and it is important to understand the molecular basis for aberrant DNA replication in tumors. Moreover, since many chemotherapies specifically target cells in S-phase, a more detailed understanding of DNA replication could allow the rational design of novel cancer therapeutics. Our lab focuses on three main aspects of DNA replication control: (1) The S-phase checkpoint, (2) Trans-Lesion Synthesis (TLS) and (3) Re-replication.