The immune system is able to recognize and eliminate cancer cells when it is optimally activated. Cancer vaccines that can activate the immune system are expected to work synergistically with other treatments to improve the survival of cancer patients. Previously, we have demonstrated that Siglec-1/CD169-expressing macrophages can stimulate very strong immune responses. Our aim is to develop a new type of cancer nanovaccine that specifically targets cancer antigens to Siglec-1/CD169-expressing macrophages. In this project we will generate nanobodies that specifically can bind human Siglec-1/CD169 and incorporate these in cancer vaccines to enable efficient uptake by Siglec-1/CD169-expressing macrophages and the activation of immune responses that can eliminate cancer.