Such studies have helped to reveal a role for P2X7 on host antigen-presenting cells in GVHD development [192], T cells in the protection from experimental autoimmune encephalitis [193], or more broadly hematopoietic cells in allergic airway inflammation [194], lung inflammation and emphysema [195], acute respiratory distress syndrome [196], mood disorders [197], and tumor immunity [198]. The gene discussed is P2RX7; the disease is graft versus host disease.