IDH1 and glioblastoma: To address if proteomic patterns vary across GBM’s histomorphologic niches, we assembled a cohort of 20 well-sampled formalin-fixed paraffin-embedded (FFPE) IDH-wildtype primary GBMs by reviewing a larger array of representative cases from our institute to normalize for sample-to-sample morphologic variations and tissue purity (Supplementary Data File 1).