SMN1 and carcinoma: Three carcinomas with decreasing active TGF-β1 tissue levels (high, median and low) were stained for p-smad-2 showing decreased nuclear staining for p-smad-2 in the malignant cells and even stronger in the SMA-positive myofibroblasts (SMA, vimentin and pan-cytokeratin staining on sequential sections, not shown).