SPP1 and neoplasm: Fibronectin is a high molecular weight glycoprotein that binds to integrins.31 Nucleolin is known to be involved in cell differentiation, adhesion, inflammation and tumor development,32 while Vimentin is an intermediate filament protein that is used as a marker of mesenchymal-derived cells.33 In this study, we focused on the role of OPN in the responses to mechanical stimulation, since OPN is known to be involved in tumor progression.19