CFU-GEMM progenitor activity is significantly increased in spleen but not the bone marrow of TSLP transgenic mice. TG and LM mice have similar numbers of myeloid CFUs in the bone marrow; but in the spleen, CFU-GEMMs were significantly increased in TG mice compared to the wild-type controls (LM). The results are presented as the average number of CFU-GEMMs ± SEM from triplicate experiments (n = 2 and n = 3 for TG and LM animals, respectively).