While mutations of the EGFR gene represent a prognostic and a predictive marker, an ALK translocation is mainly a predictive marker, as the prognosis of patients not treated with ALK-specific tyrosine kinase inhibitors (TKI) is as unfavorable as the prognosis of NSCLC patients with no detectable EGFR or ALK gene mutation (wild-type (WT) NSCLC). This evidence concerns the gene ALK and non-small cell lung carcinoma.