Recent studies have highlighted its association with periodontitis by assessing its expression in various biological samples—including GCF, saliva, gingival tissue, and serum—as a possible inflammatory biomarker.15-18 Increasing evidence indicates that the CX3CL1–CX3CR1 signaling pathway is closely associated with the pathological process of fibrosis in multiple tissues and organs. This evidence concerns the gene CX3CL1 and periodontitis.