TGFB1 and neoplasm: On one hand, as an immunosuppressive cytokine, TGFβ suppresses cytotoxic T cells to produce effector molecules, including IFNγ, and downstream STAT1 activation during tumor cell killing.51, 52 On the other hand, a high level of IFNγ downregulates ECM factors, especially the integrins, which play crucial roles in TGFβ activation.