Zhao et al. (2008) also reported that CD4+ CD103+ Foxp3+ nTreg cells migrate directly to GVHD target organs due to high expression of CCR5 and low expression of CD62L, and are able to ameliorate cGVHD severity, providing additional confirmation that Treg cell trafficking is critical for optimal protection from GVHD. This evidence concerns the gene CCR5 and graft versus host disease.