Cytokine that acts as a regulator of the activity of Nodal/BMP pathways during the establishment of bilateral asymmetry in the head and trunk of the embryo. At embryonic stage 8 is expressed in the left lateral plate mesoderm, bilaterally in the head and in a small horizontal domain coincident with the second caudal somite. By stage 9, expression in the right side of the head has disappeared and all remaining expression in both the head and trunk is on the left. The most medial domain of expression expands caudally as new somites form. By SHH signaling both in the head and in the trunk. On the left side in the head was also controlled by NODAL. Belongs to the DAN family.