Consistent with our Nodal Western blot results (Fig. 5C), we found that Cerberus-Fc reduced p-Smad2 levels in Nodal expressing breast cancer cell lines, including MDA-MB-231 and BT549, but not in cell lines where we did not detect a Nodal signal, including T47D, MCF-7 and Hs57t. Here, SMAD2 is linked to breast cancer.