The addition of plerixafor to G-CSF as first line regimen for peripheral blood stem cell (PBSC) mobilization has been shown to be safe and effective in two phase III placebo-controlled randomized studies in MM and NHL patients undergoing ASCT [15, 16] as well as in multiple phase II and retrospective studies in hard-to-mobilize patients [7, 14, 17, 19–21]. This evidence concerns the gene CSF3 and non-Hodgkin lymphoma.