SMAD2 and ulcer disease: For TGF-βR I, SMAD2, and TGFβ-1, 4 of 6 patients showed the same expression patterns; mRNA expression of TGF-βR I and SMAD2 was lower in skin around ulcers than in normal skin, while the expression of TGFβ-1 expression was higher (Fig. 4b).