SDC1 and systemic lupus erythematosus: Because Gal-9 induces apoptosis of Th1, Th17, and CD8 T cells through Gal-9/Tim-3 interaction, we first asked whether plasma cells express Tim-3, and intriguingly found that about 20% of plasma cells (CD19− CD138+) in MRL/lpr lupus-prone mice express Tim-3 (Figure.