HES1 and acute lymphoblastic leukemia: Importantly, the DEG analysis was inconsistent with the hypothesis that dimerization was only required for targets regulated by SPS sites [8, 30], present in over 20% of enhancers based on studies in a T-ALL cell line [31]: expression of dimer-dependent targets such as NRARP, Hes5, or Hes1 [8] was unchanged, suggesting that differentially expressed genes reflected an overall reduction in Notch transcriptional activity rather than selective reduction of dimer-dependent gene expression (Fig 5 and S1A Table).