On day 19 after BMT without vaccination, KGF does not change the percentage of CD8⁺tetramer⁺ cells that could respond to vaccination or the percentage of CD4⁺ cells that express Foxp3 but does increase the overall number CD8⁺tetramer⁺ and CD4⁺Foxp3⁺ cells in each mouse. B6 mice underwent T cell-depleted BMT and were treated with KGF as described in Figure 1. On day 19, frequency and total number of CD8⁺tetramer⁺ cells were determined by purifying peripheral CD8⁺ cells (combined spleens and inguinal LNs) with magnetic beads, and staining with opt-TRP1-455 tetramer. Purified CD8⁺ cells staining for tetramer (A and B, *P = .004) and splenocytes staining for Foxp3 (C,D, *P < .001) were analyzed with flow cytometry. Data are pooled from 2 experiments with similar results.