This study evaluates the electric characteristics of the BTI relative to the <i>IDH</i> mutation status.<h4>Methods</h4>To investigate peritumoral cortical excitability (CE), we applied 5258 pulses of transcranial magnetic stimulation (TMS) at the BTI of <i>IDH</i>-mutant (<i>IDH-mt</i>) and <i>IDH</i>-wildtype (<i>IDH-wt</i>) glial tumors in 39 patients. This evidence concerns the gene IDH1 and glioma.