Figure 2. . Osteoblastic cell adhesion proteins. The ECM proteins mainly composed of collagen I, vitronectin and fibronectin shared with the specific RGD sequence. Integrins and cadherins are transmembrane proteins with an extracellular domain binding ligands as well as an intracellular domain connected with cytoskeletal proteins. Cytoskeletal proteins, including FAK, talins, vinculins, β-catenin and actins, are a collection of interconnected molecules contribute together to the formation of focal adhesions (adapted from[4]).