Among the ten proteins identified, it should be emphasized that LAP3, DNAJB11, MANF, LCP1, CTSZ, PTPRC and EML4 were significantly increased in RA compared to OA and/or CPPA (with an overexpression confirmed in IHC for LAP3, MANF, LCP1, CTSZ and PTPRC). The gene discussed is PTPRC; the disease is rheumatoid arthritis.