Epigenetic modification plays an important role in transcriptional regulation As a subunit of the INHAT (Inhibitor of histone acetyltransferases) complex, SET/TAF-I beta evidences transcriptional repression activity In this study, we demonstrate that SET/TAF-I beta is abundantly expressed in neuronal tissues of Drosophila embryos It is expressed at high levels prior to and in early stages of neuronal development, and gradually reduced as differentiation proceeds SET/TAF-I beta binds to the promoters of a subset of neuronal development markers and negatively regulates the transcription of these genes The results of this study show that the knockdown of SET/TAF-I beta by si-RNA induces neuronal cell differentiation, thus implicating SET/TAF-I beta as a negative regulator of neuronal development (C) 2010 Elsevier Inc All rights reserved