S100A9 and glioblastoma: We selected a human astrocyte cell line (NHA) and five GBM cell lines (U87, T98, U118, LN229, and U251), detected the S100A9 expression level by western blotting and confirmed that S100A9 has the highest expression level in U87 cell line and the lowest expression level in LN229 cell line (Figure 5A).