Several studies have shown that early onset of acute gastrointestinal GVHD, severe clinical gastrointestinal GVHD, hematochezia, mismatched donor type, and low albumin and high serum bilirubin levels are risk factors for mortality in patients with gastrointestinal GVHD (4, 34–36). This evidence concerns the gene ALB and Hematochezia.