PLK1 and non-small cell lung carcinoma: We tested the effect of 60 nM volasertib in two of these lines (HCC4006-ER2 and HCC827-ER3) and found that the agent caused marked G2/M arrest and apoptosis (Figure 2), which supports our hypothesis that EMT enhances ER NSCLC cells' sensitivity to PLK1 inhibitors.