Gazi U, et al. - The proposition explored was that PFAPA (periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis) correlated with a change in antimicrobial peptide (AMP) expression levels, as in the case of Crohn's disease which was another autoinflammatory disorder. Tonsillar expression levels of human beta-defensin 1-2, cathelicidin, ribonuclease-7, and liver expressed antimicrobial peptide-1 were monitored by immunohistochemistry (IHC). data shed light on a possible connection between PFAPA patients with altered AMP expression as in other autoinflammatory diseases.