As speculated, Bim knockout or Mcl-1 overexpression in these resistant cell lines conferred resistance to the combination of osimertinib with an ERK1/2 inhibitor, furthering the notion that modulation of Bim and Mcl-1 critically determines the responses of EGFR-mutant NSCLC cells to osimertinib. Here, EGFR is linked to non-small cell lung carcinoma.