PADI4 and rheumatoid arthritis: Polymorphisms occur in PADI4, which are associated with a susceptibility to RA, such as in our findings, and interactions between homozygous to the GTG haplotype (rs11203366, rs11203367, and rs874881) of SNV in PADI4 and the HLA-DRB1 shared epitope (SE) allele, which are related to the anti-CCP production, as well as smoking and the presence of erosive disease of the same patients [50].