DNA replication is one of the major targets of cancer therapies, as cancer cells tend to proliferate faster than normal cells and are generally more prone to replication stress. Most of our current knowledge about DNA replication initiation, or origin firing, currently comes from model organisms, such as yeast, but their applicability to the human system is limited. It is important to study replication initiation in human cells in order to be able to exploit the findings in cancer therapies. The main objectives of this project are to identify novel players in various stages of human replication initiation and characterize the non-catalytic roles of DNA polymerase epsilon and protein Timeless in replisome assembly.