detected the expression of let-7i, lysine demethylase 3A (KDM3A), bicorticoid kinase 1 (DCLK1) and ion transport regulator 3 (FXYD3) containing FXYD domain in lung cancer tissues, then determined the regulatory relationship among them, and observed the effects of them on lung cancer cells. Here, KDM3A is linked to lung cancer.