Emergence of immature/transitional B cells after rhIL-7 administration. (A) Example of contour plot demonstrating the emergence of CD27⁻CD10⁺CD21^low/high (immature/transitional) B cells at day 28. (B) Summary data from placebo and rhIL-7 recipients confirmed a statistically significant increase of the subset of immature/transitional B cells on day 28. PBMCs were gated on CD19⁺ cells and mature CD27⁺CD10⁺ B cells were excluded.