Osimertinib, the first FDA-approved third-generation EGFR TKI for EGFR T790M-positive NSCLC treatment [25], has been recognized for its ability to attenuate the drug efflux function of ABCB1 and ABCG2, thus reversing MDR mediated by both transporters [15,26]. The gene discussed is ABCB1; the disease is non-small cell lung carcinoma.