Effects of human cytokines on colony formation of marmoset (•) and human (○) BMPCs. The effects of IL-3 on CFU-GM (A) and BFU-E (B) formation in the presence of 2 U/mL Epo, GM-CSF on CFU-GM formation (C), G-CSF on CFU-G formation (D), and Epo on CFU-E formation in the presence of 10 ng/mL IL-3 (E) were examined in serum-free cultures. The effects of Tpo were assessed using human platelet-poor plasma (F). The human cytokines effectively stimulated colony formation dose-dependently. The response patterns of BMPCs to human cytokines was similar in marmosets and humans. Data are expressed as the mean ± standard error of mean (SEM) from three separate triplicate experiments.