CDK4 and lung cancer: In conclusion, we have demonstrated that GLPT (G. lucidum extracts) inhibited cell proliferation by decreasing the protein levels of CDK4/6, cyclin D1, and Cdc25A; increasing the protein levels of p27Kip1 and p21Cip1; inducing apoptosis by downregulating Bcl-xL, survivin and Bcl-2; and upregulating DR4 and DR5 in human lung cancer cells.