Clinical studies have shown that periodontal disease with Aggregatibacter actinomycetemcomitans can exacerbate symptoms of rheumatoid arthritis (RA), but the molecular mechanisms behind this remain unclear. In a recent study, researchers conducted several experiments in a mouse model of arthritis to shed light on this topic. Their findings reveal the crucial role of macrophages and the protein caspase-11 in this context, hinting at promising therapeutic targets for RA and other periodontal infection-related diseases.