In grade III glioma, age, histological type, extent of resection, MGMT methylation status, and Ki-67 level were independent prognostic factors that affect OS in patients (Table 4), and patients with higher preoperative PNI showed a better prognosis only in the univariate analysis (HR = 0.301, p = 0.032). The gene discussed is MGMT; the disease is central nervous system cancer.