TGFB1 and central nervous system cancer: Then, TGF-β/Smad pathway-related protein expression was measured in clinical glioma samples (Figure 4a; Supplementary Figure 2A), results of which revealed upregulation of TGF-β and increased extent of Smad2/3 phosphorylation in glioma samples, while the increase tended to be more significant over the glioma stages.