Further, anti-Il1rl1 neutralizing antibody or Il1rl1 small molecule inhibitors administered after allogeneic hematopoietic cell transplantation has shown therapeutic efficacy in GVHD and GVL which was better than anticipated with the sole reduction of GVHD, suggesting a direct leukemia activity of the anti-Il1rl1 drugs17,90. Here, IL1RL1 is linked to graft versus host disease.