Glioblastoma (GBM), a particularly devastating type of brain tumor, remains a challenging and difficult cancer to treat. There are many types of cells in a GBM tumor, including tumor cells, tumor stem cells, immune cells, blood vessels, and other cells, which makes developing therapies a challenge. Macrophages are a type of immune cell found in GBM tumors. In fact, macrophages can make up to 30% of the entire tumor mass. Depending on the stimuli, macrophages are activated to an M1 (therapeutic) or M2 (toxic) state. It is generally thought that in the tumor, macrophages become activated to the toxic M2 state and aid in tumor growth through the secretion of various proteins. We are trying to promote therapeutic macrophages that fight the tumor, instead of the toxic macrophages that help the tumor grow. Excitingly, we have generated a mouse model of GBM in which the macrophages help fight the tumor - M1 (therapeutic) macrophage. These macrophages attack the tumor cells and actually help the mice live longer and result in smaller tumors. My hypothesis is that therapeutic M1 macrophages will collaborate and enhance standard of care (temozolomide and radiation) in GBM. Additionally, we would like to test our therapeutic macrophage model with additional therapies for patients with GBM to determine if more optimal combinations of therapies are possible.