TSLP is not necessary or sufficient to mediate the thymopoietic effects of KGF. All KGF-treated mice received 5 mg/kg KGF or PBS (intraperitoneally) on days 0, +2, and +4, and thymic cellularity +21 days after KGF therapy was initiated is shown. Values represent mean (±SEM). (A) Where indicated, 1 mg IL7Rα blocking antibody (A7R34) was given intraperitoneally on days −3, −1, +1, +3, and +5 (n=5-8 per group). (B) IL7^−/− mice and littermate, age-matched controls (n=5 per group). (C) Rag1^−/− mice were lethally irradiated (10 gy) and given 10⁷ bone marrow cells intravenously from γc^−/− or wild type mice (n = 3-5 per group). * indicates P < .01 and **, P < .001.