¹CRC Cell Cycle Group, Paterson Institute for Cancer Research, Christie Hospital NHS Trust, Wilmslow Road, Manchester M20 4BX, UK

²Department of Biomolecular Sciences, University of Manchester Institute of Science & Technology (UMIST), Manchester M60 1QD, UK

Correspondence to: E Hara, Paterson Institute for Cancer Research, Christie Hospital NHS Trust, Wilmslow Road, Manchester M20 4BX, UK; E-mail: Ehara@picr.man.ac.uk

The Id family of helix-loop-helix (HLH) proteins are thought to affect the balance between cell growth and differentiation by negatively regulating the function of basic-helix-loop-helix (bHLH) transcription factors. Although it has been suggested for some time that Id is involved in cell cycle regulation, little is known about the molecular mechanism of this control. Recent studies, however, have revealed that Id binds to important cell cycle regulatory proteins other than bHLH proteins. Two such proteins, pRB (retinoblastoma tumour suppressor protein) family proteins and Ets-family transcription factors are known to play key roles in cell cycle regulation, transformation and tumour suppression. Through the characterization of these pathways we will begin to understand the mechanisms by which Id controls normal and abnormal cell cycle progression. Oncogene (2001) 20, 8317-8325

Id; cell cycle; senescence; Ets; CDKs; p16^INK4a