All cases of stage IV ALK-rearranged Sq-LC showed increased expression of the Sq-LC-specific marker cytokeratin fragment (CYFRA; > 3.5 ng/ml); the CYFRA values of stage IV ALK-rearranged Sq-LC and Ad-LC were 20.2 ± 32.6 and 9.6 ± 3.6 U/ml, respectively. This evidence concerns the gene ALK and laryngotracheoesophageal cleft.