Tumour-infiltrating cDC1s and cDC2s converge on a shared CCR7⁺ activated state, but the contribution of this population to anti-tumour immunity has remained unclear. I will present new genetic models that allow the selective tracking and manipulation of these activated dendritic cells in vivo and discuss how they reveal the functional role of this activation state in cancer immunity. Using these models, we show that priming of tumour-specific cytotoxic T cells is restricted to the activated cDC state, with cDC1s and cDC2s contributing through distinct antigen presentation pathways. Moreover, activated dendritic cells are required not only for the initiation of anti-tumour T cell responses in lymph nodes but also for maintaining T cell function within tumours. Together, these findings establish the CCR7⁺ activated state as essential for dendritic cell-mediated natural and immunotherapy-driven anti-tumour immunity.