Immunotherapy, in the shape of "immune checkpoint inhibitors" (ICI), has revolutionized the treatment of many cancers. ICI alleviate tumor-induced exhaustion of anti-tumoral T-cells. Clinical effects are however limited to a minority of patients where tumors are pre-seeded with (exhausted) T-cells, i.e. immune "hot" tumors. Unfortunately in most patients tumors are poor in T-cells, also known as an immune "cold" state. Our research focuses on strategies to convert this state into a T-cell infiltrated "hot" state, which is crucial to unlock the full power of immunotherapy and achieve long-term cancer eradication. To that end, we use RNA technology to produce re-engineered antigen-presenting cells in novel ways in order to deliver a powerful cellular vaccine platform with activity in the therapeutic setting. A cornerstone of our work is the development of a humanized in vivo model allowing to deliver highly relevant preclinical data for rapid translation to early phase clinical trials.