Summary "Immunotherapy, where a patient's own immune system is activated to kill cancer cells, has taken the central stage in the fight against cancer. Interaction between checkpoint molecules such as PD-1 and PD-L1, however, can function as brakes that stops the patient's immune system from destroying cancer cells. Hence, releasing these brakes with nanomedicines can kick-start the immune system to kill cancer cells. The aim of the project is to make safe and long-lasting checkpoint inhibitor nanomedicines. The application of the Carlsberg Foundation funded PD-1/PD-L1 Blockade Bioassay is crucial to optimise drug designs and allow preclinical studies.