PADI4 and arthritic joint disease: Given the association between the G allele of rs2240335 in PADI4 and increased rheumatoid arthritis risk in East Asians [19,20], the reduction of PAD4 levels associated with the G allele of rs2240335 in Europeans [22], the role of PAD4 in NETosis, autoantibodies, and arthritis in mice [7,17], and the link between NETs, ACPAs, and human rheumatoid arthritis [4,27], we determined if rs2240335 would be associated with NETs, anti-citrullinated histone antibodies, and rheumatoid arthritis in a North American cohort.