TGFB1 and neoplasm: TGFβ also plays an important role in the context of the bone microenvironment and supports the progression of bone metastasis in PCa.490–492 Furthermore, TGFβ facilitates tumor growth through its immunosuppressive function.493,494 To target TGFβ signaling, galunisertib (LY2157299), an oral small-molecule inhibitor of TGFβR1, has been developed.495 A clinical study of galunisertib plus enzalutamide in mCRPC has been initiated (Table 10).