IL31 and rheumatoid arthritis: Based on the foregoing, the main purpose of this study was to evaluate whether recombinant human MIF (rhMIF) promotes the secretion of IL-25, IL-31, and IL-33 in peripheral blood mononuclear cells (PBMC) from control subjects (CS) and RA patients and to recognize the possible relationship between these four cytokines and their role in RA.