PECAM1 and graft versus host disease: In a study by Eyrich et al., upregulation of VCAM-1, ICAM-1, B7–1, and B7–2 was demonstrated in an allogeneic mouse model with GVHD on day 22, whereas other adhesion molecules, such as ICAM-2, platelet-endothelial cell adhesion molecule 1, E-selectin and mucosal addressin cell adhesion molecule 1 were not changed [33].