The proliferation potential of GBM cells was measured by Ki67 immuno-staining, which demonstrated that U87 cells proliferated significantly faster than U373 cells (Figure 3a, 3b), which was consistent with the results of the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays (Figure 1a). The gene discussed is MKI67; the disease is glioblastoma.