In GFs, COX-2 expression and PGE2 production are upregulated by multiple factors associated with periodontitis pathogenesis, including inflammatory cytokines (16), oral pathogens, such as Porphyromonas gingivalis and Filifactor alocis (17, 18), or bacterial virulence factors, in particular, lipopolysaccharides (LPS) and P. gingivalis-derived fimbriae (19, 20). The gene discussed is PTGS2; the disease is periodontitis.