PTGS2 and periodontitis: The results presented here not only identify a new potentially pathogenic role of GFs and highlight their important role as “non-classical” components of the immune system of the oral mucosa but also suggest that targeting the pathways that are essential for synergistic COX-2 and PGE2 induction in GFs could be clinically beneficial as an adjunctive anti-inflammatory host modulation therapeutic option in the treatment of periodontitis.