The results showed that the original GBM displayed moderate staining of FN protein (Figure 8I), and the recurrent GBM exhibited moderately strong staining of FN protein (Figure 8J), but the recurrent low-grade astrocytoma displayed weak staining of FN protein (Figure 8K), indicating that the FN expression level is decreased strongly during the progression of low-grade astrocytoma from GBM. This evidence concerns the gene FN1 and glioblastoma.