The tumor microenvironment (TME) contains a heterogenous mixture of cells that can promote the progression of tumors. New discoveries in the types of cells that populate the TME have given rise to molecular targets for therapeutic interventions. The application of immunoPET (positron emission tomography), a non-invasive diagnostic imaging modality, has the potential to non-invasively image and quantify various cell types within the TME. ImmunoPET combines the specificity and high affinity of monoclonal antibodies bearing radionuclides with the high sensitivity of PET. Dr Edwards will present his lab’s recent findings on imaging immune cells in the TME by immunoPET.