This trend was expected, as crizotinib was the first marketed ALK-TKI in the US (FDA approval in 2011), while alectinib was initially approved for post-crizotinib treatment in 2015 and received FDA approval for expanded use as a first-line agent in ALK+ NSCLC in 2017.12 Alectinib is currently the most frequently prescribed first-line ALK-TKI in patients with ALK+ NSCLC. The gene discussed is ALK; the disease is non-small cell lung carcinoma.