Ex vivo expansion of total nucleated cells (TNC) and CD41⁺ cells from human BM-derived CD34⁺cells. CD34⁺ cells were grown in IL-1, -6, -11, and SCF (S) with or without TPO (1,6,11,S or 1,6,11,S,T). Fold-increase values are mean ± SEM (n = 18, except for Flt3-ligand experiments where n = 4). Input numbers of CD34⁺/CD41⁺ cells were 857 ± 100 per culture. *P ≤ .05 comparisons are IL-1,6,11,S versus IL-1,6,11,S,T and IL-1,6,11,S,T versus the addition of FL.