Provided are methods for determining whether a glioblastoma (GBM) tumor or GBM cancer cell will be sensitive to a treatment targeting the integrin avb3 (αvβ3) pathway, comprising determining whether the GBM tumor or the GBM cancer cell expresses both avb3+ and Glut3+ along with a specific genetic signature associated with Glut3 addiction, where in alternative embodiments a cell is Glut3 addiction if the GBM tumor or the GBM cancer cell has markers consistent with the Classical or the Proneural molecular subtypes of GBM, or, expresses markers consistent with a Glut3-addicted molecular signature, e.g., as listed in FIG. 11 or FIG. 23. Also provided herein are methods of treating glioblastoma (GBM) tumors found to be sensitive to agents targeting or inhibiting the integrin avb3 (αvβ3) pathway, wherein the sensitivity is determined by methods as provided herein.
