TGFB1 and cancer: Bintrafusp alfa, a bispecific antibody targeting PD-L1/transforming growth factor β (TGFβ), binds to PD-L1 on cancer cells to block PD-1/PD-L1 interaction with T cells leading to T cell exhaustion, and captures TGFβ, blocking downstream immunosuppressive signals with the other arm [22].