We also note, at this time point, increased numbers of KLRG1+ NK cells in the Ackr2 compared with WT lungs (Supplemental Fig. 3Cii), perhaps suggesting that the process of tumor killing by NK cells early in the metastatic process produces an inflammatory environment that leads to secondary recruitment of CCR2+ NK cells in Ackr2−/− lungs. The gene discussed is ACKR2; the disease is neoplasm.