SMAD3 and neoplasm: MiR-34a regulation of tumor-associated EMT can modulate not only by EMT-TFs and tumor suppressor p53, but also some fundamental signal pathways, such as Wnt [63,64], TGF-β1/Smad3 (transforming growth factor-beta 1/Smad3), and Notch1 [65,66] (Figure 2).