Additional file 1.(a) The serum levels of IL-21 in Figure 2a. (b) The serum levels of IL-21 in Figure 3c. (c) The serum levels of IL-21 in Figure 3f. Format: TIFF Size: 446KB Download file Liu et al. Arthritis Research & Therapy 2012 14:R255 doi:10.1186/ar4100 |