MIF drives synovial macrophage release of cytokines and prostaglandins, induces the expression of disease‐promoting cytokines, regulates hypercellularity, and is required for leukocyte trafficking into the joint (Morand et al., 2006); thus, MIF is a key cytokine in diseases characterized by a disordered immune‐inflammatory response, such as RA (Morand et al., 2006). The gene discussed is MIF; the disease is rheumatoid arthritis.