Approximately 3–7% of non-small cell lung cancers (NSCLC) contain chromosomal rearrangements of anaplastic lymphoma kinase (ALK), resulting in constitutively active ALK.1,2 ALK rearranged NSCLCs are highly sensitive to ALK tyrosine kinase inhibitors (TKIs), such as crizotinib and alectinib, and intrinsic TKI resistance is rare. The gene discussed is ALK; the disease is non-small cell lung carcinoma.