SMAD2 and breast cancer: Moreover, we treated the BC cells with TGF-β2 to directly stimulate the FGF- β2/Smad2 pathway, and we observed a significant increase in Smad2 phosphorylation and autophagy levels, which was similar to the results in the cells treated with rapamycin (20 nM), an autophagy inducer (Figs. S2).