CCR7 and neoplasm: It is generally accepted that migratory DCs (e.g., cDC1) transport tumor antigens to LNs via specific chemokine receptors (e.g., CCL21/CCR7 signaling)[164,184], which activate CD8+ T cells via cross-presentation, while the cDC2 subpopulation supports CD4+ T cell activation[2,6,7].