Glioblastoma (GBM) is the most aggressive brain cancer, with most patients surviving little more than a year after diagnosis with no effective treatments being generated in decades. Our lab discovered MPO-expressing macrophages, a type of immune cells that are more abundant in longer-surviving individuals with GBM that appear to directly kill cancer cells. This project will investigate how MPO drives their cancer-killing activity, what tumour conditions activate them, and map their distribution in human samples using spatial technologies, potentially revealing a new immunotherapeutic avenue for GBM.