Human mesenchymal stem cells (hMSCs) can form various mesodermal tissues when grown under appropriate conditions. Dexamethasone (Dex) is regularly used to stimulate the osteogenic potential of hMSCs and it has recently been reported to increase the cell expansion rate. In this study we have investigated the effect of low-dose Dex treatment (10(-8) M) on the multipotency of expanded hMSCs, using histological, biochemical and molecular biological techniques. Early passage (P2-3) and late passage (P6) cells were positive (>90%) for mesenchymal adhesion cell markers (CD105/CD29/CD44/CD166/CD90) and negative (