EML4 and non-small cell lung carcinoma: EML-ALK fusion gene was firstly identified in 2007 and represents the most frequent rearrangement in NSCLC patients (accounting for approximately 95% of ALK fusion variants): it results from a translocation, specifically involving an inversion on the short arm of chromosome 2 that connects the 5′ end of the EML4 gene with the 3′ end of the ALK gene.