Otherwise, the IL-6 in GCF was higher in patients of the G3 (OSA) and G4 (P-OSA) and positively correlated with PD in G3 (OSA) and with PD and BOP (%) in G4 (P-OSA), in comparison with G2 (P) which had lower levels and negative correlations with all periodontal parameters. The gene discussed is IL6; the disease is obstructive sleep apnea syndrome.