Updated project metadata. Glioblastoma Multiforme (GBM) is an aggressive form of brain tumor, associated with poor prognosis and low survival rates, and early diagnosis is impaired by the lack of presymptomatic biomarkers. Here we used a syngenic GBM mouse model to investigate longitudinal changes in the proteome profile of serum, serum small extracellular vesicles (sEVs) and cerebrospinal fluid (CSF) during GBM progression. Motor tests were used to define a baseline, a presymptomatic and an advanced stage of tumor progression and body fluids were sampled at these time points.