Cooperation and regulatory loops of multiple nodals are essential for mesendoderm patterning in early embryos. Plays a role in mesoderm formation and may be required for neural development (By similarity). Homodimer; disulfide-linked. By dorsal mesoderm-inducing signals including activin and vegt. Not induced by wnt8 alone, but wnt8 potentiates the response to activin and vegt. Belongs to the TGF-beta family.