These results provide evidence that autologous NK cell therapy can positively impact the disease control of established low-burden MHC-I+ tumor metastases by both directly detecting and killing circulating metastatic tumor cells (Single Combat) and by leading to improved immune infiltration and cDC1 and CD8+ T-cell activation and priming (calling for backup) to establish antigen-specific control of newly established metastases. Here, CD8A is linked to neoplasm.