GVHD patients’ serum has been used to identify biomarkers related to tissue damage during the pathogenesis of GVHD (131–133) Acute GVHD biomarkers include plasma levels of IL-2 receptor subunit α (IL-2Rα), TNF receptor 1 (TNFR1), IL-8, hepatocyte growth factor (134, 135), and amphiregulin (136). Here, CXCL8 is linked to graft versus host disease.