Question: A 69-year-old Japanese woman with persistent cough visited our hospital. She was diagnosed with unresectable non-small cell lung cancer (adenocarcinoma) by histologic examination of biopsied samples during bronchoscopy. The patient was treated with pemeterexed and carboplatin, followed by maintenance therapy of pemetrexed alone. Administration of crizotinib was then initiated owing to disease progression. Although crizotinib had been discontinued owing to bacterial pneumonia in the left lung, it was reintroduced after treatment was completed.