CCL21 and neoplasm: However, we did not observe any changes in the number of DCs in the TME after NK cells transfer, which may be due to the fact that DCs are very dynamic throughout the tumor immune cycle, and when DCs phagocytose antigens in tumors, they immediately express CCR7 which is converted to the TDLN by CCL10, CCL19, and CCL21, and therefore a change in the number of DCs in the tumor after NK infusion was not observed in the tumor.