IL24 and rheumatoid arthritis: IL-24 and its receptors are widely expressed by immune cells and epithelial cells, and IL-24 elevation is associated with different autoimmune diseases, including psoriasis [10], rheumatoid arthritis [11], inflammatory bowel diseases [12], and multiple sclerosis [13], suggesting that it is a multifunctional cytokine that may play a critical role in regulating tissue inflammation and autoimmunity.