Key concepts and search terms related to periodontal disease, specific systemic conditions (e.g., cardiovascular disease, diabetes mellitus, Alzheimer's disease, etc.), relevant pathogens (e.g., Porphyromonas gingivalis, Fusobacterium nucleatum), biomarkers (e.g., IL-6, CRP, MMPs), and diagnostic technologies (e.g., biosensors, microfluidics, lateral flow assays) were employed. The gene discussed is CRP; the disease is cardiovascular disorder.