TNFRSF1B and graft versus host disease: Using the mouse TNFR2 agonist STAR2, Chopra et al. (2016) showed that exogenous TNFR2 activation protected from acute graft-versus-host disease (GvHD) after allogeneic hematopoietic stem cell transplantation (allo-HCT) via host Treg cell expansion.