Effects of different hormones and different oxygen concentrations on CFU formation (A) Comparison of the number of CFUs in different groups. (B) Comparison of the total number of cells in different groups. (C) Comparison of the colony types in different normoxia groups. The presence of testosterone significantly increased the numbers of CFU, particularly CFU-Es. (D) Comparison of the colony types among different hypoxia groups. The presence of testosterone significantly increased CFU numbers, particularly CFU-Es. Norepinephrine significantly inhibited colony formation and cell amplification under normoxic and hypoxic conditions. Data are presented as the mean + standard deviation. *P<0.05 and **P<0.01. CFU, Colony-forming unit; CFU-GM, colony-forming unit-granulocyte/macrophage; CFU-MIX, colony forming units-mixed; BFU-E, burst-forming unit-erythroid; CFU-E, colony-forming units-erythroid.