Volume 110 (2006), pp. 305–314

All papers submitted to Clinical Science are received on the understanding that the material presented is the author(s)' original work and has not been published elsewhere.

All authors who submit work to Clinical Science are aware of this policy when submissions are made.

It has been brought to the attention of the Editorial Board that this Review Article by Cynthia Portal-Celhay and Guillermo I. Perez-Perez contains a significant amount of text that has been reproduced directly from a number of other publications and that very little original input has been made. The Editorial Board are therefore retracting this paper.