In addition, these characteristics of ALK-positive lung cancer could be useful in difficult-to-diagnose cases (e.g., IHC-positive and FISH-negative or IHC-negative and FISH positive cases) [21, 22] However, these strategies are not supported by any reports or clinical trials, and to our best knowledge, little is known regarding the recurrence patterns for the various molecular subtypes. This evidence concerns the gene ALK and lung carcinoma.