Examples include elafin for skin GVHD5, regenerating islet-derived 3α (REG3α) for gastrointestinal GVHD6, hepatocyte growth factor (HGF), cytokeratin fragment 18 (KRT18) for liver GVHD7,8, interleukin-2 receptor α (IL-2Rα), tumour necrosis factor receptor 1 (TNFR1), IL-8, IL-7, and soluble DNAX accessory molecule-1 (DNAM-1) for systemic GVHD7,9,10. Here, HGF is linked to medical procedure.