Targeting EGFR activating mutations, 90% of which present as an exon 19 deletion (Del19) or exon 21 point mutation (L858R), with first and second generation EGFR tyrosine kinase inhibitors (EGFR-TKIs; e.g., erlotinib, gefitinib and afatinib) and T790M resistant mutation with third generation EGFR-TKIs (e.g., osimertinib; TAGRISSOTM or AZD9291) has provided significant clinical benefit in patients with NSCLC harboring these mutations, representing a successful example for targeted therapy against lung cancer 3, 4. The gene discussed is EGFR; the disease is lung cancer.