MKI67 and glioblastoma: Significantly, compared with 6 cycles of TMZ chemotherapy, extended TMZ treatment obviously prolonged the OS of newly diagnosed GBM patients regardless of Ki67 expression levels (patients with Ki67 < 35%: 19.80 months vs. 46.00 months, HR = 2.57, 95% CI: 1.19 ~ 5.56, P = 0.004; patients with Ki67 ≥ 35%: 13.80 months vs. 24.90 months, HR = 2.92, 95% CI: 1.48 ~ 5.75, P < 0.001) (Figure 7A).