c-Myc is a transcriptional regulator involved in carcinogenesis through its role in growth control and cell cycle progression. Here we attempt to relate its role in stimulating the G1-S transition to the ability to affect functioning of key cell cycle regulators, and we focus on how its property of modulating transcription of a aide range of target genes could explain its capacity to affect multiple pathways leading to proliferation, apoptosis, growth, and transformation. (C) 2001 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved.