In this study, the interference capability of the siRNA-c-kit was validated (Supplementary Figure S5) and upon transfection into the PC9/Gr and HCC827/Gr cells, we observed a significant decrease in resistance to gefitinib (Figure 2D), which suggesting that c-kit might be served as a promising target for overcoming gefitinib resistance in lung cancer. The gene discussed is KIT; the disease is lung cancer.