Methods, processes, uses, and pharmaceutical compositions are provided herein for mobilizing hematopoietic progenitor cells and/or cancer stem cells from bone marrow into peripheral blood, comprising the administration of an effective amount of an inhibitor of GTPases, such as a Cdc-42 specific inhibitor alone or in combination with one or more additional agents. Specifically, methods are disclosed for mobilizing hematopoietic stem cells into a subject's peripheral blood. In particular, embodiments of the method involve specific inhibition of the Cdc42 GTPase to increase the numbers of hematopoietic stem cells into a subject's peripheral blood of a subject.