Despite there being no differences between ‘clinically defined’ LC and NLC, a trend toward an increase in the transcript levels of the main IFN-I pathway components (IFN-α and IFN-β) was observed among LC participants, suggesting that these IFN-I subtypes may play a key role in the development of LC symptoms [27]. This evidence concerns the gene IFNA1 and laryngotracheoesophageal cleft.