Role of TGF-β and TNF-α in the suppression of CFU-GMs and long-term culture-initiating cell (LTC-IC) proliferation by SP(1-4).

Clonogenic (panel A) and LTC-IC (panel B) assays were performed in the presence of 10 nM SP(1-4). Parallel cultures contained anti–TGF-β or anti–TNF-α. The results are expressed as the mean ± SD of 6 experiments, each performed with a different healthy BM donor. *P < .05 versus SP(1-4) alone; **P < .05 versus SP(1-4) plus anti–TGF-β.