The Center for Protein Engineering (Centre d'Ingéniérie des Protéines: CIP) is a multidisciplinary research Center of the University of Liège (Belgium).The Center aim is to offer an integrated approach to the determination of the structure of proteins and to the analysis of their functional properties.Six closely interacting research groups constitute the framework of the Centre: Applied Quantum Chemistry and Modelling, Bacterial Biodiversity, Physiology and Genetics, Biological Macromolecules and Biochemistry, Biological Macromolecule crystallography, Enzymology and Protein Folding, Functional genomics and plant molecular imaging.