HOXA9 enhances hematopoietic differentiation of hESCs in OP9 coculture. (A) Schema of hESC hematopoietic differentiation system based on OP9 coculture and endpoint analysis (left panel). Representative flow cytometry displaying how HEPs (CD45⁻CD31⁺CD34⁺) and blood cells (CD45⁺/CD45⁺CD34⁺) are identified within the human GFP⁺ population (right panel). (B) Enforced expression of Hoxa9 enhances the differentiation into primitive blood cells (CD34⁺CD45⁺) and total blood cells (CD45⁺). (C) CFU read out from day 15 EBs confirms a significantly increase in hematopoietic clonogenic potential of the HOXA9-hESC blood derivatives. Scoring of CFU reveals a skew toward G-CFU in Hoxa9-transduced progenitors (right pie charts). (D) Ectopic Hoxa9 remains highly expressed throughout the differentiation. Relative expression is shown normalized to undifferentiated hESCs. Data are presented as mean ± standard error of the mean for 3 independent experiments. G, granulocyte; M, monocyte; GM, granulocyte-macrophage; E, erythroid.