To develop new strategies to optimize palbociclib-mediated tumor growth inhibition in lung cancer, we tested the effects of palbociclib in 13 different annotated NSCLC cell lines with absent p16 expression (validated CKDN2A somatic mutations or hypermethylation), and in two tumor cell lines with RB-null, p16-intact expression which were included as negative control for CDK4/6 inhibition (H1734 and H2009) (Figure 1 and data not shown). The gene discussed is RB1; the disease is non-small cell lung carcinoma.