According to this study, among 21 molecularly profiled CUP patients (miRNA 92-gene molecular cancer classifier assay, CancerTYPE ID) predicted as NSCLC, four harbored EML4-ALK fusion genes and one patient who was suitable for treatment with an ALK (Anaplastic Lymphoma Receptor Tyrosine Kinase) inhibitor showed a prolonged benefit. Here, ALK is linked to cancer.