EGFR and lung cancer: Metastases to the brain remain a significant problemin lung cancer,as treatment by most small-molecule targeted therapies is severelylimited by efflux transporters at the blood–brain barrier (BBB).Here, we report the discovery of a selective, orally bioavailable,epidermal growth factor receptor (EGFR) inhibitor, 9,that exhibits high brain penetration and potent activity in osimertinib-resistantcell lines bearing L858R/C797S and exon19del/C797S EGFR resistancemutations.