TGFB1 and gestational choriocarcinoma: Given the role of SALL4 in the activation of the TGF-β/SMAD signaling pathway to promote epithelial–mesenchymal transition and metastasis in other cancers, and the upregulation described in gestational choriocarcinoma, we assessed SALL4 protein expression in complete mole and postmolar choriocarcinoma samples.