CD44 and central nervous system cancer: These included extracellular matrix receptors long-studied as mediators of GBM invasion (e.g., PTPRZ1; Fig. 2c) [5], as well as the marker of glioma stem cells of the Verhaak mesenchymal subtype, CD44. We found several target sequences expressed in 10–35% of neoplastic cells within individual tumors and across 5–10% of GBM cases (Fig. 2d, Additional file 3: Fig. S2A).