Rapamycin/IL-2 combination therapy transiently augments NK cell frequency. Thawed PBMCs were stained for viability, CD56, CD3, and CD16. A: The number of CD56+CD3− NK cells of PBMCs are shown for individual subjects. B: The average ± SD frequencies for CD56hiCD16+ (open squares), CD56hiCD16− (closed triangles), and CD56loCD16+ (closed circles) subsets of CD56+ NK cells within the live lymphocyte gate are shown. Statistical significance was determined by a one-way ANOVA, noted in the graph. Significance from time 0 to each time point was determined using a paired Student t test and is indicated with an asterisk. *P ≤ 0.05, **P ≤ 0.01.