Our meta-analysis strongly suggests the existence of at least two distinct entities of PTMC. Incidental PTMC has different clinical characteristics and a much lower recurrence rate than nonincidental PTMC, suggesting that management protocols should be re-considered. Additional studies with standardized data collection are required to explore potential differences between subgroups of nonincidental PTMC.

Short β-peptides can mimic natural peptide hormones, as has been shown with a cyclo-β-tetrapeptide (1) that displays micromolar affinity to human somatostatin receptors. β-Peptides are thus a promising new class of peptidomimetics with potential high bioavailability due to their excellent resistance against proteases.

Inhibiting TNF-α or src kinases may be a therapeutic option to normalize barrier integrity and cytokine release in airway diseases associated with barrier dysfunction.