Comparison of blood leukocyte counts in WHIM patients after treatment with plerixafor and G-CSF. Parameters on x-axis are defined as follows: (1) “Plerixafor peak,” the mean ± SEM of the peak absolute blood leukocyte subset counts of WHIM patients 1, 2, and 3 in response to administration of both 0.16 and 0.24 mg/kg doses of plerixafor in this study; (2) “Off therapy,” the mean ± SEM of absolute blood leukocyte subset counts for all values determined on days −1 and −2 of the phase 1 study (Figure 1); and (3) “G-CSF,” the mean ± SEM of all available absolute blood leukocyte subset counts of WHIM patients 1 and 2 during treatment with daily G-CSF at 1-3 μg/kg. Horizontal dotted lines indicate the normal range.