P2X7 activation can promote the activation and proliferation of CD4+ T cells in an IL-2 dependant manner [86] and can help promote the metabolic fitness, maintenance and survival of memory CD8+ T cells [121,122], thus the possibility remains that P2X7 may contribute to the activation and survival of donor effector T cells in GVHD. The gene discussed is CD4; the disease is graft versus host disease.