CDK4 and cancer: Correlation between the half-maximal inhibitory concentration (IC50) of palbociclib and expression of Rb and LMWE across all cancer cell lines revealed that cell lines with an intact G1/S transition (Rb+/LMWE−) were significantly more sensitive to the CDK4/6 inhibitor and that this sensitivity was further increased by autophagy inhibition (Fig. 5n and Supplementary Fig. 18e).