The Myc/Max/Mad network comprises a group of transcription factors that co-interact to regulate gene-specific transcriptional activation or repression. This gene encodes a protein member of the Myc/Max/Mad network. This protein has a basic-Helix-Loop-Helix-zipper domain (bHLHzip) with which it binds the canonical DNA sequence CANNTG, known as the E box, following heterodimerization with Max proteins. This protein is likely a transcriptional repressor and an antagonist of Myc-dependent transcriptional activation and cell growth. This protein represses transcription by binding to DNA binding proteins at its N-terminal Sin3-interaction domain. [provided by RefSeq, Jul 2008]