SMAD3 and squamous cell carcinoma: Immunohistochemical staining detected a significant elevation of TGF-βRI and p-SMAD3 in both subgroups of adenocarcinoma and squamous cell carcinoma compared with normal cervix glandular epithelia and squamous epithelia, respectively (adenocarcinoma, PTGF-βRI < 0.001, Fig. 5d, Pp-SMAD3 = 0.023, Fig. 5e; squamous cell carcinoma, PTGF-βRI < 0.001, Fig. 5f, Pp-SMAD3 < 0.001, Fig. 5g).