CX3CL1 and periodontal disorder: Upregulation of CX3CL1 expression has been observed in response to pathogen-associated molecular patterns (PAMPs), including P.gingivalis LPS, indicating that the CX3CL1–CX3CR1 system may contribute to leukocyte infiltration in periodontal tissues and the progression of periodontal disease.15 Consistent with these findings, our study demonstrated increased CX3CL1 and TNF-α expression in gingival tissue samples exhibiting inflammatory overgrowth.