TGFBR2 and small cell lung carcinoma: Both phosphorylation of Smad2 and induction of SMAD7 by TGF-β were observed in TβRII-expressing cancer cells, but not in control SCLC cells that expressed green fluorescent protein (GFP) alone (H82-GFP cells and H345-GFP cells; Figure 2a and b).