TGF-β, VEGF, and CXCL12 expression is increased in both BM and spleen from wild-type and Gata1^low mice and inhibition of TGF-β signaling reduces expression of TGF-β but not that of VEGF or CXCL12. Expression levels were analyzed by quantitative RT-PCR analyses and are normalized to those detected in BM from untreated Gata1^low mice. Results are presented as mean (±SD) of 3 independent determinations with 3 mice per experimental point. Values observed in untreated wild-type and Gata1^low mice are presented as gray and pink boxes, respectively. Values statistically different (P < .05) between untreated wild-type and Gata1^low mice and vehicle- and SB431542-treated Gata1^low mice are indicated by ^& and *, respectively. Similar differences in TGF-β expression among the various groups were also detected by microarray profiling and are not included in Table 3, because they were <2-fold, the cutoff that defined differences in expression in this Table.