SMAD3 and neoplasm: The blocking of Slit2/Robo1 signaling by R5 attenuated TGF-β1 phosphorylation of Smad2 and Smad3 in Lovo cells (Figure 4D), SW480 cells (Figure S3A), and tumor tissues of ApcMin+ mice (Figure 4E) compared with mIgG-treated groups.