Important data in graft versus host disease (GVHD), in humans and mice, demonstrated that dual blockade of CTLA-4 and LAG-3 using tetravalent Ig synergistically inhibited T-cell proliferation, suppressed T-cell responses thereby preventing the incidence of acute GVHD and decreasing GVHD mortality rates [97]. Here, LAG3 is linked to graft versus host disease.