TGFB1 and cancer: Metastasis-initiating cells enriched for the core stem cell transcription factor SOX2 can self-impose a quiescent and immune-evasive state through autocrine expression of DKK1, an inhibitor of the WNT signalling pathway.8 Notably, these cells show increased TGF-β signalling when in a quiescent state, accompanied by reductions in WNT, MYC and NF-κB signalling.8 WNT is a potent mitogen for stem and progenitor cell pools that has been implicated in both tumour initiation and the metastatic progression of lung121 and breast122,123 cancers.