The ERC proof-of-concept project CONQUEST (COmpanion Nanodiagnostics for QUantifying Epr and Stratifying patients to Targeted nanotherapies) aimed to explore the possibilities of commercializing a first-of-its-kind platform technology for visualizing and quantifying the Enhanced Permeability and Retention (EPR) effect. EPR results from leaky tumor blood vessels and from defective lymphatic drainage, and it is crucial for proper therapeutic performance of tumor-targeted nanomedicine formulations. Recent insights have shown that the EPR effect is highly heterogeneous, varying strongly from cancer type to cancer type, and from patient to patient. Predictive biomarkers are therefore needed which can capture this heterogeneity in EPR-mediated nanomedicine accumulation and which allow for imaging-based patient pre-selection, initially in clinical trials and later on also in routine clinical practice. Within CONQUEST, a theranostic nanocarrier platform has been developed which can be radiolabeled and imaged, and which can be employed to help to differentiate potential responders (patients with high EPR) from non-responders (patients with low EPR). Intellectual property (IP) has been obtained on the chemical composition of the nanocarrier, and further IP is currently being generated to provide a strong basis for starting a spin-off company, which will aim take this innovative construct and concept to the clinic and to the market.