The present invention relates to a method and composition for mobilizing cells from a subject by blocking CXCR4, beta-
adrenergic receptors, GPCRs, or any combination thereof. In some embodiments, the cells are hematopoietic stem cells. In some embodiments, the method further comprises the administration of G-CSF. The present invention also relates to a treatment method, a method for qualifying a subject for treatment, and a method for preparing a subject for treatment by blocking CXCR4, beta-
adrenergic receptors, GPCRs, or any combination thereof. In some embodiments, the cells are hematopoietic stem cells. In some embodiments, the treatment is for
cancer. In some embodiments, CXCR4 is GPC-100. In some embodiments, the method further comprises the administration of G-CSF.