CDK2 and lung cancer: Besides, we also revealed the reduction of CDK2 expression in 95D cells after transfection with Ches1 expression vector (Figure 5E, p<0.05), which could partly explain our results and was consistent with our previous study demonstrating that up-regulation of CDK2 was critical for TLR9 signaling to stimulate the proliferation and cell cycle entry of human lung cancer cells [4].