Provided here is an easily accessible introduction to themechanisms of DNA replication, regulation and thebiochemistry of cell cycle control. An overview of thisrapidly developing field is presented to orient the reader,followed by a series of contributions by leading researcherssummarizing recent results on selected topics, such asprotein phosporylation, tumor suppressor genes, and signaltransduction in prokaryotic and eucaryotic systems. Thereader will gain an overview of our current understanding ofDNA replication and the cell cycle, and a selection ofuseful recent references for further reading.