Graft versus host disease (GVHD) is a condition that can arise after a patient has a bone marrow transplant. In acute cases of GVHD, epithelium in organs such as the skin, gastrointestinal (GI) tract, and liver are damaged. Generally, liver biopsies are not performed specifically to diagnose GVHD. Liver biopsies are commonly obtained only when immunosuppressive therapy is not successful and liver function abnormalities exist or when liver disease is the only symptom that manifests. In acute cases of GVHD, liver biopsies are often obtained to diagnose conditions secondary to the liver disease such as viral infection.