TYK2 gene mutations are genetically linked to ankylosing spondylitis, psoriasis, Crohn’s disease, ulcerative colitis, type 1 diabetes, multiple sclerosis (MS), lupus erythematosus (SLE), and rheumatoid arthritis (RA) (Parkes et al., 2013). This evidence concerns the gene TYK2 and rheumatoid arthritis.