P2RX7 and graft versus host disease: Whether host (murine) P2X7 contributes to GVHD development in humanised mice remains unknown, but a study of bone marrow chimeras using P2rx7 gene knockout and wild-type mice indicated that P2X7 on host APCs but not donor cells was the main contributor to GVHD development in an allogeneic mouse model [16].