With the purpose of investigating further the TGF-β/Smad signaling role in SPA tumor development, Smad3 and phosphorylated Smad3 protein levels were measured by immunochemistry in 161 patients with SPAs, including 59 invasive (36.6%) and 102 noninvasive (63.4%) lesions (129). Here, TGFB1 is linked to neoplasm.