ALK and neoplasm: To better select the patients for this type of treatment, a proper method of anaplastic lymphoma kinase (ALK) gene detection must be used according to the diagnosis standards and the main options applied in clinical practice are fluorescence in situ hybridization (FISH), immunohistochemistry (IHC), reverse transcriptase-polymerase chain reaction (RT-PCR), next-generation sequencing (NGS), liquid biopsy, and new potential biomarkers such as circulating tumor cells (CTCs), cell-free DNA, and exosomes are being investigated [3].