EGFR and non-small cell lung carcinoma: One important finding is that Topo IIα levels were elevated in several EGFRm NSCLC cell lines with acquired resistance to osimertinib, which was confirmed in over 60% of tissues from patients with EGFRm NSCLC who relapsed following treatment with EGFR-TKIs, including osimertinib, constituting a critical foundation for targeting Top o II to overcome acquired resistance to osimertinib and possibly other EGFR-TKIs.