The purpose of this study is to test whether the addition of the drug plerixafor to treatment with chemotherapy and G-CSF can better activate your bone marrow stem cells to improve the chances of transplant. The study will look for the activation of a certain type of blood cell, called CD34+ cells in patients who receive plerixafor, chemotherapy and G-CSF. The investigators will follow the number of patients that achieve the target numbers of CD34+ cells. The number of patients achieving the target level of CD34+ cells, and the total number of CD34+ cells, will be compared to the numbers in previous studies testing just chemotherapy and G-CSF, without plerixafor.