TGFB1 and prostate cancer: TGFβ's actions can be blocked using a TGFβRI inhibitor (SD‐208) in vitro37 and, more recently, TGFβ inhibition has been used as anti‐tumor therapy in preclinical models of myeloma,38, 39 breast cancer,40, 41, 42 and prostate cancer.43 Interestingly, several of these inhibitors are now in cancer clinical trials as anti‐tumor drugs (e.g. NCT02452008 and NCT0140106244, 45).