TOP2A and non-small cell lung carcinoma: These data clearly demonstrate that enforced overexpression of the ectopic TOP2A gene in EGFRm NSCLC cells attenuates the ability of osimertinib to induce DNA damage and apoptosis and to decrease cell survival, suggesting an essential role of Topo II inhibition in mediating therapeutic efficacy of osimertinib against EGFRm NSCLC cells.