['Human mesenchymal stromal cells (MSC) have considerable potential for cell-based therapies, including applications for regenerative medicine and immune suppression in graft-versus-host disease (GvHD). However, harvesting cells from the human body can cause iatrogenic disorders and in vitro expansion of MSC carries a risk of tumorigenesis and/or expansion of unexpected cell populations.', 'Given these problems, we have focused on umbilical cord, a tissue obtained with few ethical problems that contains significant numbers of MSC. We have developed a modified method to isolate MSC from umbilical cord, and investigated their properties using flow cytometry, mRNA analysis and an in vivo GvHD model.', 'Our study demonstrates that, using umbilical cord, large numbers of MSC can be safely obtained using a simple procedure without in vitro expansion, and these non-expanded MSC have the potential to suppress GvHD.'] Does human umbilical cord provide a significant source of unexpanded mesenchymal stromal cells?