Crizotinib and ceritinib are the first- and a second-generation ALK TKI, respectively, approved for the treatment of patients with ALK-positive advanced non-small cell lung cancer (NSCLC), and lorlatinib is a third-generation ALK TKI approved for previously treated ALK-positive metastatic NSCLC (Recondo et al. 2018) (also see https://www.drugs.com/history/xalkori.html, https://www.drugs.com/history/zykadia.html and https://www.drugs.com/history/lorbrena.html). The gene discussed is ALK; the disease is non-small cell lung carcinoma.