Furthermore, although there are no reliable diagnostic tests to predict treatment, with the exception of six previously validated diagnostic biomarkers of GVHD (IL-2 receptor-α; tumour necrosis factor receptor-1; hepatocyte growth factor; IL-8; elafin, a skin-specific marker; and regenerating islet-derived 3-α, a gastrointestinal tract-specific marker) (16), a novel acute GVHD risk score has been created to define high-risk acute GVHD at the onset (17). Here, HGF is linked to acute graft versus host disease.