Three most relevant and most frequently used factors for the prognosis of RA have been identified, i.e. high disease activity including high number of swollen joints, positivity for rheumatoid factor (RF) and/or anti-citrullinated protein-peptide antibodies (ACPA), and the early presence of structural damage; these prognostic factors are incorporated in current treatment recommendations for the management of RA [20]. The gene discussed is PRTN3; the disease is rheumatoid arthritis.