Taken together, our results confirm previous findings, that chronic gingival inflammation is associated with increased local protein citrullination as well as PAD2 and PAD4 expression in gingival tissue of patients with periodontitis, and additioanally, that this process appears to be independent of the presence of P. gingivalis and A. actinomycetemcomitans leukotoxin. The gene discussed is PADI4; the disease is periodontitis.