CSF3 and graft versus host disease: The main sources for isolation of HSPCs, including umbilical cord blood (UCB), mobilized peripheral blood with granulocyte colony-stimulating factor (G-CSF), and BM.48,49 UCB has important advantages such as easy to acquire, easy availability, less stringent for HLA matching, lower incidence of GVHD, and lower risk for transmission of infectious diseases than peripheral blood and BM.