Recognizes the DNA sequence 5'-ATTAA-3' (By similarity). Transcriptional repressor. Regulates the differentiation of both endothelial and blood cells. Plays a role in embryonic dorsoventral patterning by regulating bmp expression. May establish anterior identity. Functions in the embryo to regulate liver development. Functions extraembryonically to generate organ chirality. Expressed in embryonic endothelial and blood lineages. From late-blastula stage, expression is restricted to the dorsal marginal region of the extraembryonic yolk syncytial layer (YSL). By the onset of gastrulation, expressed in the entire dorsal half of the YSL. Post-gastrulation, expression appears in both anterior and posterior lateral plate mesoderm by the 3-somite stage. Posteriorly, expression is in the intermediate cell mass (ICM), which contains both endothelial and blood precursors. Subsequently expressed in the developing endothelial cells including the endocardium until the onset of circulation (24 hpf) and disappears completely by 30 hpf, at which point expression is seen in the thyroid and liver primordia. Also expressed in the developing biliary tree and pancreas. By dhama/boz downstream of canonical wnt-signaling.