We examined, in a consecutive single-operator series of 122 GBM patients surgically treated from 2013 to 2017 at Sapienza University of Rome, the correlation between sex, age, preoperative KPS, presenting with seizures, and extent of resection (EOR) with OS, PFS, and postoperative KPS, along with the prognostic value of mutations of IDH1, MGMT, ATRX, EGFR, and TP53 genes and of Ki67. This evidence concerns the gene MKI67 and glioblastoma.