In line with this hypothesis, periodontitis was independently associated with rheumatoid arthritis in multiple epidemiological studies (reviewed in ref. [64]) and a specific set of anti-citrullinated peptide antibodies (ACPA), which was present in rheumatoid arthritis patients, was associated with coronary artery calcification, a well established surrogate marker of coronary atherosclerosis [65]. The gene discussed is PRTN3; the disease is rheumatoid arthritis.