Recently, it was reported that IL‐2Rα/IL‐27 pathway displayed contrast effect in allogeneic transplantation rejection In humanized xenogeneic GVHD NOD/SCID model, IL‐27 favoured human placenta–derived MSCs to promote generation of CD4+IL‐10+IFN‐γ+ T cells and alleviate GVHD symptoms.10 Here, CD4 is linked to graft versus host disease.