ALK and non-small cell lung carcinoma: The FDA has approved five ALK inhibitors, which have been the first-line standard of care for patients with NSCLC harboring ALK rearrangements [17], including the first-generation ALK inhibitor (crizotinib [64, 65]), the second-generation ALK inhibitors (ceritinib [66], alectinib [67], and brigatinib [68]), and the third-generation ALK inhibitor (lorlatinib [69]).