CDK2 and neoplasm: Western blot analysis of the tumor tissue lysates showed greater inhibition of phospho-C-MYC (ser62) and hTERT in the combination group compared with palbociclib or CDK2 siRNA alone (Figure 6G), which confirmed again that C-MYC is involved in the ability of combined CDK2 and CDK4/6 inhibition to overcome acquired resistance to CDK4/6 inhibitor.