Transforming growth factor-β receptor III downregulation in prostate cancer: is inhibin B a tumor suppressor in prostate?

Abstract
The transforming growth factor-β (TGF-β) pathway plays dual roles in cancer, inhibiting epithelial cell growth under normal physiologic conditions, but promoting invasion and metastasis once growth inhibitory responses are lost. Two recent papers show that TGF-β receptor III is the most common TGF-β pathway component downregulated in prostate cancer. Here, we discuss the implications of these findings and what it may mean about the biology of this disease.