## 2 Materials and Methods
### Samples  
To test the standardized methods, a total of 34 patients with gliomas (n = 16) or meningioma (n = 18) were recruited within the period December 2016 to October 2018 (Table 1A,B). The project was approved by the Palermo Ethics Committee I (number 11)(2018). Written informed consent was obtained from each subject. The study included only patients without a systemic infection or other tumors and capable of providing consent on their own. The GBM patients selected were only those desiring to participate in the study and in which a maximal safe tumor removal was deemed feasible considering neurological status, including neuroradiological imaging evaluation (Table 1A,B). Brain glial tumors with corpus callosum infiltration were excluded. For meningiomas, we included patients with primary diagnosis of meningiomas, without previous radiotherapy. All brain surgeries were performed by the same neurosurgical team, including the Neurosurgical Unit Chairman [PERSON], senior author of the manuscript and his collaborator [PERSON]. Blood and pathological tissue samples were taken from each patient on the day of the surgery. For each patient, blood samples were collected at different time points, just before surgery (Before Surgery, BS), and at one week (After Surgery 1, AS1), and one month (After Surgery, AS2) after surgical tumor resection, and were processed for serum separation. A brain MRI post-gadolinium within 72 h (when feasible) and at one week, and at three months from discharge, was performed to verify tumor recurrence for correlation with the results of our analysis. Patients affected by GBM, after the definitive histopathological analysis, underwent the STUPP protocol therapy as usual [41; 42]. Patients affected by brain meningiomas WHO GI or II after complete tumor removal were followed at our Outpatient Clinic. Patients affected by anaplastic meningiomas underwent oncological management and radiotherapy.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & & & & & **(A)** \\ \hline \multirow{2}{*}{**Pt\({}^{*}\)**} & \multirow{2}{*}{**See/Age** (years)**} & \multirow{2}{*}{**Brain Site**} & \multirow{2}{*}{**Histopathology \({}^{b}\)**} & & **Follow-Up** \\ \cline{3-6}  & & & & **BIS-AS1-AS2** & & **Clinical/Months** \\ \hline \multirow{2}{*}{1} & \multirow{2}{*}{M/65} & \multirow{2}{*}{Left temporal-peritrigional} & \multirow{2}{*}{HGG GBM IV WHO NOS: GFAP+LDH+, Synaptofosin-;} & \multirow{2}{*}{C} & \multirow{2}{*}{14} \\  & & & & & Kief7+ \(<\)10\% & \\ \multirow{2}{*}{2} & \multirow{2}{*}{M/57} & \multirow{2}{*}{Right frontal} & \multirow{2}{*}{HGG GBM IV WHO NOS: p53+, GFAP+, CAM 52-; Kief7 - 60\%} & & \multirow{2}{*}{C} & \multirow{2}{*}{10} \\  & & & & & Kief7+ \(<\)10\% & \\ \multirow{2}{*}{3} & \multirow{2}{*}{M/60} & \multirow{2}{*}{Left temporal-periential} & \multirow{2}{*}{HGG GBM IV WHO NOS: p53+, GFAP+, CAM 52-; Kief7 - 60\%} & & \multirow{2}{*}{C} & \multirow{2}{*}{12} \\  & & & & & Kief7+ \(<\)3\% & \\ \multirow{2}{*}{4} & \multirow{2}{*}{M/55} & \multirow{2}{*}{Left fronto-temporal} & \multirow{2}{*}{HGG GBM IV WHO IDS: GGP+, Panck+, Kief7 - 30\%} & & \multirow{2}{*}{C} & \multirow{2}{*}{8} \\  & & & & HGG GBM IV WHO IDI mutant Fnamtions HGG: GFAP+, & & & \\ \multirow{2}{*}{5} & \multirow{2}{*}{F/65} & \multirow{2}{*}{Right fronto-temporo-parietal} & \multirow{2}{*}{LDH+, p53+ 3\%; Kief7 - 30\%} & & \multirow{2}{*}{C} & \multirow{2}{*}{9} \\  & & & & & Kief7+ \(<\)5\% & \\ \multirow{2}{*}{6} & \multirow{2}{*}{F/70} & \multirow{2}{*}{Left fronto-temporal-peritrigional} & \multirow{2}{*}{HGG III WHO NOS: High differentiated elements: GFAP+, and 5-100+, sympathoint