EML4 and lung cancer: Since 2007, when echinoderm microtubule-associated protein-like 4 (EML4)-ALK fusions were first described in lung cancer (Soda et al. 2007), several ALK tyrosine kinase inhibitors (TKIs) spanning three generations have been developed and are already approved for routine use in Europe: crizotinib (first generation); ceritinib, alectinib, and brigatinib (all second generation); and lorlatinib (third generation) (Elsayed and Christopoulos 2021).