HOXA9 is expressed in the HEPs during differentiation of hESC. (A) Schema of hESC hematopoietic differentiation system based on EB formation. (B) Kinetics of the emergence of HEPs during the hematopoietic differentiation protocol (left). Time course expression of HOXA9 during EB hematopoietic development (right). The expression of endogenous HOXA9 correlates with the HEPs emergence throughout EB differentiation. (C) Quantitative polymerase chain reaction analysis in isolated cell populations demonstrating that HOXA9 expression is enriched in the HEP population. Gene expression is shown relative to nonhematopoietic cells. (D) A 60-fold reduction of HOXA9 expression on day 15 EB in comparison with definitive CB-CD34⁺ hematopoietic cells. Relative expression is shown normalized to undifferentiated hESCs. Data represent mean ± standard error of the mean for 3 independent experiments.