FN1 and brain neoplasm: Although the components of the ECM in brain tumor tissue have not been fully elucidated yet, it has been reported that amorphous ECM at the invasive front of proliferating GBM is highly expressed such as glycosaminoglycans (GAGs), especially hyaluronic acid (HA)31, 32, 33, and they strongly up-regulated fibrous and adhesive ECM proteins, (e.g., collagen IV, fibronectin, and laminin)34.