Researchers at Hokkaido University and collaborators reported that immune checkpoint blockade can still trigger the first wave of tumor rejection even when cDC1 dendritic cells are absent. Their results suggest initial effector responses can arise through alternative routes, but checkpoint therapy may fail to establish lasting immune memory without cDC1. The findings directly challenge a widely held assumption that cDC1 presence is required for durable protection following checkpoint blockade, and they clarify where biology may diverge between early tumor clearance and long-term immune surveillance.