To address the potential role of miR-574-5p in TLR9 signaling enhanced progression of human lung cancer cells, we evaluated the effect of down-regulation of miR-574-5p on TLR9 signaling enhanced progression of 95D cells and found that down-regulation of miR-574-5p could obviously reduce the progression of 95D cells in vitro and in vivo. The gene discussed is TLR9; the disease is lung cancer.