HES1 and acute myeloid leukemia: In another microarray gene expression profiling study CD34+ bone marrow cells from AML patients had NOTCH1 and NOTCH2 expression similar to the normal donor samples, however the levels of NOTCH targets HES1 and DELTEX1 were lower in AML cells indicating reduced NOTCH signalling despite the expression of NOTCH receptors (Kannan et al. 2013).