CD4 and rheumatoid arthritis: To further investigate the specificity of DN T cells, their possible linear differentiation depending upon TcR signaling, we sorted by flow cytometry CD4− CD8− DN T cells from four additional RA subjects (subjects 13–16, Table 1), together with autologous, activated, CD11c+ CD11b+ CD86+ myeloid DC that served as antigen presenting cells (APC) in co‐cultures experiments.