Effect of TGFβ under different cytokine combinations.

Cultures were initiated in media with different combinations of cytokines (SCF + IL3 + EPO, SCF + EPO, IL3 + EPO) in the presence or absence of TGFβ (as indicated in the figure). After 4 days, all cultures were reseeded without TGFβ in fresh medium with the full complement of SCF, IL3, and EPO. Examples of hemoglobin profiles from day 8 cultures (4 days after reseeding). See Table 1 for numerical evaluations.