CDT1 and lung cancer: To further validate its expression, RT‐qPCR and Immunoblotting were conducted to assess CDT1 expression in lung cancer cells (H460, A549, and HCC1588) and normal lung cells (MRC5), revealing that compared with MRC5 cells, CDT1 levels were strikingly suppressed in H460, A549, and HCC1588 cells, and A549 cells with most downregulated CDT1 level were adopted for subsequent experiments (Figure 1B).