TNF and rheumatoid arthritis: In addition, they also secrete cytokines such as TNF-α, IL-23, IL-1β, and IL-12, which lead to dysfunctional inflammatory responses that develop into conditions characterized by refractory or severe chronic inflammation, such as rheumatoid arthritis (RA) (31), metabolic syndrome-associated disorders (including type 2 diabetes and atherosclerosis), osteoarthritis, asthma, Crohn's disease, and Alzheimer's disease (32, 33).