LRG1 (leucine-rich α-2 glycoprotein 1) is a myelopoiesis modulator known to facilitate CD34 and myeloid progenitor growth by antagonizing the effects of transforming growth factor (TGF-β) [44], but has also been reported to be upregulated in GVHD patients [45]. Here, CD34 is linked to graft versus host disease.