The expression of IL-6 transcript was measured 2 h post infection (p.i.), whereas the level of secreted IL-6 in conditioned culture media was measured at 2, 6, and 24 h p.i. In this experimental setup P. gingivalis was a potent and rapid inducer of IL-6 mRNA expression (2 h) in a MOI-dependent manner for all tested strains and conditions. The gene discussed is IL6; the disease is infection.