CD4 and rheumatoid arthritis: Accordingly, Hsp70 is shown to elevate CD4+IL-17+ (Th17) T helper cell frequencies and shift Th17/T regulatory (Treg) balance, while CD4+IFN-γ+ (Th1) T helper cells decrease as the/ratio between Th1 and CD4+IL-4+ (Th2) decreases in an autologous way through IL-6 modulation in RA [1].