*2.7. Data Analyses*

The data analyses were divided into two parts (Figure 2). The first part focused on the cortical level to investigate differences in GMI between language-positive and language-negative nTMS points (Figure 2). The second part focused on the subcortical level to assess differences in fiber tractography between nTMS-based DTI FT using language-positive or language-negative nTMS points as ROIs by means of investigating short fibers for short-distance connections (U-fibers), long fibers projecting to the contralateral hemisphere (Cross-F), and fibers projecting to the cerebellum (Cereb-F; Figure 2).

**Figure 2.** Overview of procedures and analyses. This scheme summarizes the study's steps of analyses, which were performed based on data derived from language mapping by navigated transcranial magnetic stimulation (nTMS) and nTMS-based diffusion tensor imaging fiber tracking (DTI FT). Language-positive and language-negative nTMS points were used separately for the different analyses. The study cohort included 20 patients with left-hemispheric glioblastoma multiforme (GBM).
