This Phase 2 study was designed to assess the safety and hematological activity of AMD3100 (plerixafor) in patients with non-Hodgkin's lymphoma (NHL) or multiple myeloma (MM) who were predicted to be unable to mobilize ≥2*10^6 CD34+ cells/kg within 3 apheresis days. Patients with NHL and MM were eligible to enter the study if they had undergone cyto-reductive chemotherapy, were to undergo autologous transplantation, and met the inclusion/exclusion criteria.