TGFB1 and neoplasm: In the mammary epithelium, attenuation of TGF-β signaling using a dominant negative type II transforming growth factor-beta receptor (TβRII) resulted in lobular alveolar hyperplasia and an increased rate of tumor formation in conjunction with a TGF-α transgene [8]; however, decreased pulmonary metastasis resulted when dominant negative TβRII was expressed along with a c-Neu transgene [8,9].