The tumor specimens removed from five patients with surgically treated, histologically proven astrocytoma or GBM, including a low-grade astrocytoma with local GBM transformation, a GBM with local recurrence, a GBM with local recurrence and then remote brain metastasis, a GBM with spinal metastasis, and a GBM with local recurrence and then low-grade astrocytoma progression, were examined by IHC staining with an antibody specifically against FN. This evidence concerns the gene FN1 and glioblastoma.