Because the patient's leukemia cells carried ALK rearrangement and were refractory to conventional salvage therapy, we decided to administer crizotinib based upon its potential efficacy for the disease.5 After the approval of an institutional review board and written informed consent from her guardians, the patient received crizotinib, 280 mg/m2, twice a day, without concomitant chemotherapy except for intrathecal therapy (12 mg methotrexate, 25 mg cytarabine and 10 mg hydrocortisone). Here, ALK is linked to leukemia.