Recent studies that included other biomarkers, not only aAbs, have already shown improvements in the identification of RA (Conti et al. 2020; Kurowska et al. 2020; Regueiro et al. 2019), but the sensitivities found for Anti-CD26 aAbs are higher in comparison (Assmann et al. 2020). This evidence concerns the gene DPP4 and rheumatoid arthritis.