In the present study, we concluded that IL-1β is an important factor in the induction of RA by infection with A. actinomycetemcomitans, but our results obtained using a CAIA model indicate that IL-6 secretion in paws was also critical for the induction of RA by infection with A. actinomycetemcomitans. The gene discussed is IL6; the disease is rheumatoid arthritis.