Furthermore, endothelial cell adhesion molecules are highly expressed after allotransplantation especially in GVHD-affected tissue, and soluble E-selectin (CD62E) serum levels are increased during acute GVHD whereas levels of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1) are only increased in chronic GVHD [6–8]. The gene discussed is ICAM1; the disease is acute graft versus host disease.