KRAS and neoplasm: In previous studies, systemic let‐7b administration was able to prevent and treat Kras‐driven lung tumors.[21, 22, 23] The current study is the first investigation of the efficacy of aerosolized let‐7b in lung cancer prevention and found that let‐7b given via aerosol exhibited striking tumor inhibition in both the benzo[a]pyrene (B[a]P)‐induced and a syngraft model of lung cancer without causing detectable side effects.