N-(4-Hydroxymethylbenzyl) Cyclam is an impurity of Plerixafor (P580500), a hematopoietic stem cell (HSC) mobilizer that inhibits the CXCR4 chemokine receptor and blocks binding of its ligand, stromal cell-derived factor-1-α (SDF-1-α). This agent was approved on Dec. 15, 2008, as treatment in combination with granulocyte-colony stimulating factor (G-CSF) to mobilize HSCs to the peripheral blood for collection and subsequent autologous transplantation in patients with non-Hodgkin''s lymphoma (NHL) and multiple myeloma (MM).