HES1 and acute myeloid leukemia: Activation of Notch signaling was observed in BMSCs after co-culture with AML cells, as demonstrated by the increased expression of Notch receptors and Notch target genes HES1 and HEY1. In addition, we found that the expression of TNAP was increased in BMSCs after Notch activation through immobilized recombinant Jagged1.