The HEATR1 gene is expressed at levels comparable with HA-1 and P2X5 in GVHD target tissues. Expression of CD45, HEATR1, HA-1, P2X5, and IIp45 (a representative ubiquitously expressed gene) in cDNA tissue panels was evaluated by real-time quantitative PCR. The level of expression of each gene is shown relative to gene expression measured in B-LCLs, which are susceptible to lysis by the minor H antigen specific CTL after normalizing to the expression of a housekeeping gene PBGD. Data are representative of multiple experiments for each gene.