The “poor mobilizer” group was defined according to the Italian Group for Stem Cell Transplantation (GITMO) criteria [62]: lymphoma/myeloma patients in whom, after adequate mobilization (G-CSF 10 μg/kg if used alone or ≥5 μg/kg after chemotherapy), the circulating CD34+ cell peak was <20/μL up to 6 days after mobilization with G-CSF, or up to 20 days after chemotherapy and G-CSF, or if they yielded <2 × 106 CD34+ cells per kg in ≤3 aphereses. The gene discussed is CSF3; the disease is plasma cell myeloma.