As reported in results section, MRM findings indicate that two specific C-terminal HPT fragments (VGYVSGWGR and VTSIQDWVQK) and two specific A1AG1 fragments (YVGGQEHFAHLLILR and SDVVYTDWK) might be applied as novel biomarkers for the diagnosis and prognosis of RA. This evidence concerns the gene MRS2 and rheumatoid arthritis.