Chronic graft-versus-host disease (cGVHD) is a prevalent and highly lethal condition affecting stem cell transplant recipients. Unfortunately, biopsies are a painful, invasive and slow procedure that cause discomfort to patients and does not yield rapid results. The National Cancer Institute seeks licensees to commercialize this improved method for detection of diseases that are characterized by the presence of rapidly-dividing cells using deuterated water as a label for dynamic measurement of in vivo cellular kinetics.