Furthermore, given P2X7 activation can upregulate the co‐stimulatory molecules CD80 and/or CD86 on myeloid cells in vitro30 and in an allogeneic mouse model of GVHD,31 the relative amounts of these cell surface molecules on each cell type were examined (Supplementary figure 4). The gene discussed is P2RX7; the disease is graft versus host disease.