In this study, Xue et al. identified miR-200miRNAs as potent suppressors for lung adenocarcinoma metastasis. They show that miR-200regulates the functional interaction between cancer cells and CAFs at least in part by targeting Notch ligand Jagged1 and Jagged2 in cancer cells and inducing Notch activation in adjacent CAFs, providing new insight into the interaction between cancer cells and CAFs as a mechanism to promote metastatic potential.