In later works, it will be necessary to evaluate the expression of the canonical and non-canonical receptors of MIF at the mRNA level to understand the mechanisms that regulate their expression, as well as to quantify the levels of the canonical ligands of CXCR2, 4 and 7, CXCL12 and CXCL8, in serum of RA patients evaluated by DAS28-ESR to precisely know the role of these molecules in the different clinical activity groups. This evidence concerns the gene CXCL12 and rheumatoid arthritis.