With respect to B-ALL, Notch target HES1 triggers the activation of poly ADP-ribose polymerase1 (PARP1), leading to B-ALL cell apoptosis in a cell type-specific manner.505 These findings suggest that Notch signaling might regulate the fate of tumor cells in a context-dependent way through various intricate mechanisms. This evidence concerns the gene HES1 and acute lymphoblastic leukemia.