PECAM1 and graft versus host disease: An exploratory study analyzing specific membrane proteins, predictive of acute GVHD, on serum EVs isolated from 41 MM patients, for which serum samples were collected before and after (+28, +58, +92, +119, +147, and +179 days) transplant or at disease relapse, reported that CD146 (melanoma cell adhesion molecule1) expression positively correlated with an increased risk of GVHD, while CD31 (platelet endothelial cell adhesion molecule) and CD140-α (platelet-derived growth factor receptor alpha) expression was indicative of a lower risk of developing this transplant-related complication [53].