Division of Endoscopy;
National Cancer Center Hospital(Japan);
Division of Exploratory Research;
Institute of Medical Science;
University of Tokyo;
Division of Hematopoietic Stem Cell Transplantation;
National Cancer Center Hospital(Japan);
Clinical Laboratory Division;
National Cancer Center Hospital(Japan);
Cytomegalovirus gastritis; Hematopoietic stem cell transplantation; Cytomegalovirus antigenemia; Esophagogastroduodenoscopy; Graft-versus-host disease;