In liver GVHD without gastrointestinal involvement, a rare occurrence (3% of GVHD patients), REG3α and HGF concentrations were elevated compared to asymptomatic patients but were like liver gastrointestinal GVHD, non-GVHD hyperbilirubinemia, and isolated skin GVHD. This evidence concerns the gene REG3A and graft versus host disease.