ENTPD1 and graft versus host disease: Finally, mice injected with PBMCs from human donors with the intronic rs10748643 SNP in the ENTPD1 gene (encoding CD39), which results in higher proportions of CD39+ Tregs and greater suppressive capacity [131], had worsened GVHD compared to NSG mice injected with PBMCs from donors without this SNP [132].