TGFB1 and breast cancer: Interestingly, increased matrix rigidity has been shown, in vitro, to induce more active tumour invasion and osteolytic destruction of MDA-MB-231 breast cancer cells, via increased integrin β3 mediated expression of TGF-β and PTHrP (Page et al., 2015), and demonstrates the important role of mechanobiology in breast cancer metastatic invasion.