In this project, we hypothesized that stromal/immune cells in the TM promote GBM cell invasion. Our hypothesis is based on our preliminary data generated using our unique multiple-sampling scheme and single-cell/single-nucleus analysis performed on matched TM-, tumor core- and SVZ-dissociated tissues of 3 genetically diverse GBM patients. Specifically, we found that the Activated Leukocyte Cell Adhesion Molecule (ALCAM) is upregulated in the TM compared to matched tumor core and SVZ.