Plerixafor is primarily used in hematopoietic stem cell transplantation. It helps mobilize stem cells from the bone marrow into the bloodstream so they can be collected and used for autologous stem cell transplantation in patients with certain cancers, such as non-Hodgkin’s lymphoma and multiple myeloma. It works by blocking the interaction between CXCR4 and its ligand SDF-1, which promotes the release of hematopoietic stem cells into the peripheral blood. Plerixafor is typically used in combination with granulocyte-colony stimulating factor (G-CSF) when patients are poor mobilizers. This enhances the efficiency of stem cell collection through apheresis. It is not used as a standalone treatment but plays a critical supportive role in improving transplant outcomes.