SDC1 and glioblastoma: To further disclose the relationship of SDC1 and TGM2 with radiosensitivity of GBM, we detected the cellular expression levels of SDC1 and TGM2 by Western blot assay and found that they increased orderly in U251, U251R and U87 cells (Figure 2A), which has a positive correlation with the radiosensitivity as shown in Figure 1A. Here, we applied U87 cells as naturally radioresistant cells and U251R as acquired radioresistant cells, both compared to U251.