NSCLC-derived cell lines and Ba/F3 cells that were transduced with clinically relevant exon 20 insertions know to be associated with resistance to 1G/2G EGFR-TKIs, such as Y764_V765insHH, A767_V769dupASV, and D770_N771insNPG, showed comparable sensitivity to afatinib and osimertinib. The gene discussed is EGFR; the disease is non-small cell lung carcinoma.