IL17A and laryngotracheoesophageal cleft: However, upregulated mRNA levels of these cytokines in CC and LC biopsies compared to HC biopsies have not corresponded with increased amounts of secreted proteins [25, 27], and Carrasco et al. furthermore found that the amount of IFN-ƴ (Th1) and IL-17-A (Th17) producing T-cells were lower in both CC and LC biopsies than in HC biopsies [27].