We therefore detected the increase of expression of seven proteins (LAP3, DNAJB11, MANF, LCP1, CTSZ, PTPRC and EML4) in RA biopsies that was confirmed by IHC except for DNAJB11 for which levels of expression were already elevated in inflamed OA biopsies. The gene discussed is CTSZ; the disease is rheumatoid arthritis.