To the best of our knowledge, this is the first study showing that CDK2 and −4/6 are responsible for linker phosphorylation of SMAD2 in NSCLC, suggesting a possible therapeutic approach, e.g., by inhibition of CDK4/6 using Palbociclib, an approved drug for breast cancer [52]. Here, CDK2 is linked to non-small cell lung carcinoma.