CDK4 and non-small cell lung carcinoma: Using two distinct RET-fusion positive NSCLC cells, LC-2/ad (CCDC6-RET) and Ba/F3-KIF5B-RET (KIF5B-RET), they detected the highest synergistic effect combining alectinib with palbociclib, a CDK4/6 (cyclin-dependent kinase 4 and 6) inhibitor.