In Western blots, no cross-reactivity with recombinant human (rh) AgRP, rhArtemin, rh beta IG-H3, rhCripto-1, recombinant drosophila Decapentaplegic, rhGDNF, rhLAP, rhLatent TGF-beta 1, rhLefty-A, rhMIS, rhNeurturin, recombinant mouse (rh) Nodal, rmPerse