Brain tumor stem cells (BTSCs) are a subset population within tumors that are widely believed to be responsible for tumor recurrence, due to their ability to self-renew, differentiate, migrate, and initiate tumor propagation. Given these unique features, the selective targeting of BTSCs with novel therapies may prevent tumor recurrence. Stemina will progress efforts to determine BTSC biomarkers of efficacy by assessment of additional BTSC and glioblastoma multiforme (GBM) lines for in vitro studies as well as execution of in vivo studies in this Phase II project. Specifically, Stemina proposes to increase the robustness of the Phase I in vitro studies by expanding metabolomics analysis to additional BTSC lines derived from GBM, in collaboration with the Mayo Clinic and the University of Wisconsin-Madison. Stemina will evaluate treatment efficacy in vivo using the Mayo Clinic?s expertise in orthotopic mouse models to create in vivo models for each of the BTSC lines used in vitro. Metabolomics will be performed in plasma from these models to establish in vivo biomarkers of efficacy which will be validated and compared to in vitro biomarkers. Stemina expects to identify common biomarkers from in vitro and in vivo studies that can be translated to a commercial product.