TGFβ:: the molecular Jekyll and Hyde of cancer

Transforming growth factor-beta (TGF beta) signalling regulates cancer through mechanisms that function either within the tumour cell itself or through host-tumour cell interactions. Studies of tumour-cell-autonomous TGF beta effects show clearly that TGF beta signalling has a mechanistic role in tumour suppression and tumour promotion. In addition, factors in the tumour microenvironment, such as fibroblasts, immune cells and the extracellular matrix, influence the ability of TGF beta to promote or suppress carcinoma progression and metastasis. The complex nature of TGF beta signalling and crosstalk in the tumour microenvironment presents a unique challenge, and an opportunity to develop therapeutic intervention strategies for targeting cancer.