Applying predictive regression models, we found that the basal expression of p-p38 and IkBa in memory CD4+ T cells, p-cJun in naïve, and memory CD4+ T cells, and p-NFkB and CD86 in myeloid dendritic cells and classical monocytes differentiated between healthy donors and RA patients. The gene discussed is JUN; the disease is rheumatoid arthritis.