TNF and graft versus host disease: Based on our results demonstrating reduction in TNF-α concentrations and percentage of PD-1+CD8+ T cell population in vivo, together with decrease in T cell proliferation and proinflammatory chemokine concentrations as well as increase in Treg population and IL-10 concentration in vitro, AMSC might have immunomodulative effect related to the inhibition of activation, proliferation, differentiation, and migration of donor T cells, eventually delaying acute GVHD progression.