Enhancer identification in K562 cells using the DLR assay with KLF-Ps. (A) The constructs used in the reporter assay system are depicted. The pGL4.10 constructs containing respective KLF-Ps only were set as negative controls. The pGL4.10 constructs with KLF-Ps and enhancer HS2 were employed as positive references. The pGL4.10 constructs with DHSs under investigation in the place of HS2 upstream of KLF-Ps were used to evaluate the enhancer activities of DHSs. (B-K) Enhancer activities evaluation of the 23 DHSs in K562 cells. The firefly luciferase activity was normalized to that of Renilla luciferase. The relative luciferase activities of KLF-Ps–only constructs were normalized as 100%. DHSs with significantly (p < 0.01) higher activities than that of the negative control were defined as enhancers. Standard deviations were shown as error bars above each column. Asterisks indicate the statistically significant differences between the addition of DHSs and the KLF-Ps only in K562 cells ***p < 0.001, **p < 0.01.