Recent reports indicate that Let‐7 miRNAs post‐transcriptionally suppress PD‐L1 and PD‐1 expression in the TME, suggesting that let‐7 miRNAs may promote antitumor immunity in vivo.[13, 35] We therefore investigated if aerosolized let‐7b miRNA could effectively block mouse lung cancer development and progression and exhibit a favorable safety profile. The gene discussed is PDCD1; the disease is lung cancer.