CCR2 and neoplasm: One reason could be the decreased presence of myeloid‐derived suppressor cells (MDSCs).[36] Previous studies suggest that tumor‐derived CCL2 recruits CCR2+ MDSCs, which in turn impedes the infiltration of CD8+ T cells.[37] Our flow cytometry analysis supports this mechanism, suggesting that over time, intermittent aerosolized delivery of let‐7b reduces the number of suppressive myeloid cells (G‐MDSCs) as well as Tregs within tumors.