Accumulating studies have demonstrated that HIF-1α is significantly elevated in a lupus murine model, rheumatoid arthritis patient synovial fluids, and psoriatic lesions and peripheral blood via the secretion of proinflammatory cytokines (IL-17, IL-33, and IL-6, respectively) to mediate the inflammation and immune response [52–56]. Here, IL33 is linked to rheumatoid arthritis.