It has been reported that, in many autoimmune diseases, such as rheumatoid arthritis (RA) [134], systemic lupus erythematosus (SLE) [135], Sjogren’s syndrome [136], Grave’s disease [137], and Inflammatory Bowel Disease (IBD) [138,139,140], where inflammation plays an important role, the number of MCs and blood levels of IL-33 are increased [26]. The gene discussed is IL33; the disease is rheumatoid arthritis.