Pretreatment with KGF combined with androgen blockade additively restored thymopoiesis early after allogeneic BMT. Lethally irradiated B6 recipients of allogeneic (BALB/c) bone marrow were left untreated (BMT Control) or pretreated with KGF, leuprolide acetate, or KGF + leuprolide acetate and analyzed for thymocyte cellularity at day 28 after BMT alongside age-/sex-matched, unmanipulated B6 control animals (non-BMT Control). Data shown are mean absolute numbers (± SEM) of (A) total thymocytes and of the thymocyte subsets: (B) CD8⁻CD4⁻ double-negative, (C) CD8⁺CD4⁺ double-positive, (D) CD4⁺CD8⁻ single-positive, and (E) CD4⁻CD8⁺ single-positive. The data are representative of 4 independent experiments with 4 to 5 mice per group. *P < .05 compared with untreated BMT recipients; #P < .05 compared with KGF-treated or leuprolide acetate-treated BMT recipients.