TNF and graft versus host disease: Unlike TNFα-TNFR1 signaling pathway which is involved in different deleterious mechanisms such as increased inflammation and tissue damage in myocardial ischemic injuries and toxic effect in myocardial infraction [41, 42], TNFα-TNFR2 signaling supports pro-angiogenic and regenerative mechanisms like protective effect in graft versus host disease (GVHD) [43, 44], adult infract myocardium [42], heart ischemic injuries [45] and aging [46, 47].