Recognizes the DNA sequence 5'-ATTAA-3'. Transcriptional repressor. Regulates the differentiation of both endothelial and blood cells. Probably plays a role in the proliferation of vascular endothelial cells during blood vessel development. Establishes anterior identity at two levels; acts early to enhance canonical wnt-signaling by repressing expression of tle4, and acts later to inhibit nodal-signaling by directly targeting nodal/nr1 and nodal2/nr2. May play a role in liver development. Induces heart development (By similarity). Expressed in the most dorsoanterior endomesoderm of the blastula and gastrula embryo, and later is restricted to the forming liver diverticulum.