With respect to the NFkB1 (rs28362491, ins/del ATTG) polymorphism, the previous studies documented that it may affect the susceptibility to various diseases, e.g., cancer (Bu et al. 2007; Cartwright et al. 2016), autoimmune disorders including ulcerative colitis (Karban et al. 2004) or cardiovascular disease in patients with RA (López-Mejías et al. 2012). This evidence concerns the gene NFKB1 and rheumatoid arthritis.