CD4 and rheumatoid arthritis: Interestingly, two-color immunofluorescence also detected that patients with RA increased both CD4+ IFN-γ+ and CD4+ IL-4+ cells in the synovial tissues with more favorable Th1 response over Th2 (ratio Th1:Th2 = 1.58:1) as shown in Supplementary Figure 1.