59% of LC cases in the Lund cohort were IHC positive for TTF-1, while 44% were IHC positive for Napsin A. 75% of the TTF-1 positive LC cases also showed positive Napsin A expression, while no case was Napsin A positive but TTF-1 negative. This evidence concerns the gene TTF1 and laryngotracheoesophageal cleft.