In treatment-naïve ALK+ NSCLC patients, a phase III study demonstrated that the investigator-assessed progression-free survival was significantly improved with alectinib versus crizotinib.[16] Unlike crizotinib, alectinib has effective CNS penetration that causes better CNS efficacy.[17,18] Also, alectinib showed better tolerability than crizotinib despite the longer treatment duration in patients with Asian treatment-naïve ALK+ NSCLC patients.[13] For ALK+ ALCL, there is no randomized control study to compare the efficacy and safety of alectinib and crizotinib. This evidence concerns the gene ALK and non-small cell lung carcinoma.