SMAD3 and inflammatory breast carcinoma: Consistent with the previously reported abrogated TGF-β signaling pathway in IBC tumors and even more so in emboli (30, 31), culture of SUM149 and IBC-3 cells in 3D reduced the phosphorylation of SMAD2 and SMAD3 compared with adherent cells (2D) grown on plastic dishes (Figure 1C).