TGFB1 and cancer: TGF-β might also suppress the expression of perforin, granzyme A/B and Fas ligand, and thereby neutralise the effector function of cytotoxic T cells.68 There is also evidence indicating that reversal of cancer-mediated immune suppression can be achieved by neutralisation of TGF-β.69 However, the exact role of TGF-β in MSI-H/MMR-D patients treated with immune checkpoint inhibitors is unclear and needs to be further examined.