Within the multinational phase-III study ALEX the rates of CNS response in first-line patients with ALK-positive NSCLC and measurable CNS lesions at baseline for crizotinib were 50% (95% CI 28-72) compared to a CNS response rate of 81% (95% CI 58-95) with alectinib, resulting in a cause-specific hazard ratio of 0.16 (95%CI 0.10-0.28). The gene discussed is ALK; the disease is non-small cell lung carcinoma.