Our data indicate that phenotyping markers CD4, CD45RA, CD11c for the identification of CD4+ T cell subsets and myeloid dendritic cells, and p-p38, IkBa, p-cJun, p-NFkB, and CD86 as relevant functional markers could be used to analyze unstimulated PBMCs by flow cytometry for diagnosis and stratification in RA. Here, JUN is linked to rheumatoid arthritis.