The patient experienced no significant toxicity.[22] Recently, a retrospective study reported that some lung tumors with EGFR exon 20 insertion mutations were sensitive to osimertinib.[23] A phase II clinical trial to assess osimertinib as a treatment for EGFR exon 20 insertion mutant NSCLC is currently ongoing (NCT03414814). The gene discussed is EGFR; the disease is non-small cell lung carcinoma.