CD4 and rheumatoid arthritis: In the absence of stimulation, the percentage of TH-17 cells (CD3+CD4+IL-17+) was higher (p < 0.05) in RA SF (1.5 ± 0.72%) compared with RA PB (0%) and normal PB (0.04 ± 0.02%) (Figures 1 and 2).