Dysregulation of ST2/IL-33 signaling and suppression of tumorigenicity 2 (ST2) marker production is observed in various inflammatory diseases such as cardiac disease [13–16], inflammatory bowel disease (IBD) [17–20], graft-versus-host disease (GVHD) [21–28], and type-2 diabetes [29–32]. This evidence concerns the gene IL1RL1 and graft versus host disease.