A mouse thyroid-specific enhancer-binding protein (T/EBP) gene and its flanking regions have been cloned and completely sequenced. The gene consists of 2 exons and exhibits high similarity (83-97%) to the rat sequence throughout the coding region and including an intron and up to 1.3 kbp upstream to the ATG initiation codon. A cDNA clone encoding human T/EBP has been also isolated and sequenced. Comparison of the deduced amino acid sequence of T/EBP revealed an extensive identity of 98% between mouse and the human protein.